Monday, August 11, 2014

Mixed Feelings for Eucalyptus dalrympleana

I try to start these blog posts with some kind of catchy reason why you should love the plant being profiled.  When it comes to Eucalyptus dalrympleana (USDA hardiness zones 8 to 11), there are just too many reasons to pick just one.  So instead of my normal format, this whole post will support the following reasons to love (or hate) this beautiful Euc.

E. dalrympleana has showy, vanilla
scented blooms that can be messy
Reason #1, Love: Its flowers smell like vanilla / Hate: The flowers also make a huge mess

In its native range of southwest Australia, Eucalyptus dalrympleana blooms through late summer.  At Kew, our specimens burst into flower in early August, and the blossoms linger through to September.  This species of Eucalyptus usually has clusters of three flowers, but some specimens from the northern tableland may have clusters of as many as seven flowers.

Although the very frilly blooms fall to bits and make a giant mess below the tree, I think that's a flaw worth forgiving.  The burden of sweeping the pathways at least one day a week is lightened if you can pause to enjoy being enveloped in their soft vanilla scent.

Reason #2, Love: Its leaves smell like cinnamon / Hate: It is constantly shedding leaves

Although many of the most familiar species of Eucalyptus have a soft blue cast to their leaves, E. dalrympleana has shining green foliage.  The attractive green foliage makes this plant a bit easier to place in the landscape than the more striking, blue-leaved Eucs.  When crushed, the leaves smell strongly of cinnamon.

Fruit and foliage of E. dalrympleana
The mountain gum near Kew's aquatic garden has been dropping leaves the whole time that I've been here.  Daisy and I usually have to rake them up at least once a week.  Some weeks Jim the volunteer has to rake them up too.  It's frustrating to think of the other things we could be doing with our time if this tree would just take a break.  However, this tree is easy to forgive because raking doesn't always take too terribly long, and when you step on or rake up the brown, dead leaves everything smells like cinnamon.

Reason #3, Love: In August, it makes the whole area smell like pumpkin pie / Hate: In August, you may have some "hay fever"

I know that so many other foods besides pumpkin pie contain both vanilla and cinnamon, but for some reason this tree just smells like pumpkin pie.  The week that the flowers really started to come in, Jim, Daisy and I were working around the trees at the aquatic garden.  Jim casually asked if I'd ever had pumpkin pie.  "Of course I have," I replied, "We have it every Thanksgiving."

This Eucalyptus is especially floriferous in August
He went on to casually mention that the last intern from the U.S. brought in a homemade pumpkin pie, and that he'd really enjoyed it.  At first I thought he was fishing for some pie (he may well have been), but when time passed and I couldn't shake a hankering for pumpkin pie, I realized that the tree was responsible for his comments.  Probably 100 feet all around these trees smelled strongly of the dessert.  Who could help but reminisce about pie when the spot you've been working for the past few hours smells so delicious?

Although I do love the smell of sweet pumpkin pie while I work, this plant has also been giving me some irritating allergies (or as they say in the U.K., "hay fever").  The overload of pollen has been giving me itchy, runny eyes, the sniffles, and some sinus pressure.  It hasn't stopped me from going out of my way to walk through the flowers on my way to the lockers yet though.

Really beautiful, but constantly
shedding, bark

Reason #4, Love: Its peeling, snow white and cinnamon bark / Hate: It is constantly shedding bark

Although the flowers and scent are nice, what really draws visitors up to these trees is the incredibly attractive bark.  Most of the surface is clean and white, but as is true with many Eucs, the bark peels.  This species will loose huge swathes of cinnamon red bark.  The bark looks really attractive while it's still on the tree.  Yet the bark is a bit irritating when it's scattered all below the tree.  We're constantly picking up chunks of bark from the lawn, paths, and raking it out of the beds below.

Reason #5, Love: Its sinuous, twisting wood and open habit / Hate: Fear of dropping limbs

E. dalrympleana has strong, heavy branches that are held nearly horizontally from the trunk.  This feature gives the trees a very open, savanna-like feel.  It also can be quite dangerous.

View from the inside of this mountain gum
One windy day, while I was intently trying to snap a clear shot of the flowers for this post, a visitor ambled up beside me.  "We call this tree the widdah-makah," said a young man with a thick Australian accent.  I didn't quite understand what he was saying at first, but I guess they call this tree the "widow maker" where he's from.  He explained that although the habit is beautiful, it's also a deadly combination.  Extremely heavy wood held at such an angle is prone to drop without much warning.  A heavy limb from up to 120 feet overhead can kill a person.  Thus the nickname.  "Men would go into the bush, but they wouldn't come back."

Kew's arborists keep an eye on this specimen, along with all the other trees on the property.  If you look up into the canopy, you can see the measures they have taken to prevent any falling limbs.  They remove any branches that they decide are dangerous, and they even tie supports to hold up the limbs that they suspect may fall.  Homeowners should avoid planting these trees in heavily populated areas and consult with an arborist for regular maintenance.

Reason #6, Love: Its sap looks like red spaghetti / Hate: Its sap will stain any pavement below the tree

Although the wound has nearly healed, you can
spot the red strands of sap eeking out of the cut
If you prune any tree, the wound will drip with sap until it begins to heal.  In my experience, the cut usually looks a bit damp for a bit, then dries up.  The sap of E. dalrympleana doesn't behave like any other sap I've seen before.  When it eeks from a wound, it comes out in thick, long, spaghetti-like strips.  The sap is a brilliant red, which makes the wounds quite showy.

Although this looks really very interesting, the sap does fall eventually.  If it falls on a pathway below, the sap can stain the pathway with red, sticky dots.

This tree is beautiful, adaptable, easy to love for all of its virtuous and even easier to forgive for all of its failings.  That is why this attractive Eucalyptus would make a valuable addition to any large garden or landscape.

If you have any questions, comments or suggestions, please feel welcome to leave a comment or send me an email.

To see more photos from this week, be sure to check out the album "Mixed feelings for this Eucalyptus" on the Plante on Plants Facebook page.  "Likes", shares and comments are appreciated.

All photos and videos were taken by Amanda Plante at the Royal Botanic Gardens, Kew unless otherwise stated in the caption.

  • Center for the International Trade in Endangered Species database
  • Kelly, S.; Chippendale, G.M.; Johnson, R.D.  (1969).  Eucalypts.  Melbourne: Thomas Nelson (Australia) Ltd., page 38
  • Kew's Living Collections database
  • The International Union for Conservation of Nature and Natural Resources Red List of threatened species
  • The Plant List website
  • The Royal Botanic Gardens, Kew website and staff

Saturday, August 2, 2014

Stipa ichu -- the other hair grass

I've been a fan of Mexican hair grass, or Stipa tenuissima, long before I knew I wanted to be a horticulturalist.  When we teach landscape plant identification at the University of Tennessee, this Stipa always garners interest. While working in the garden, visitors would frequently stop to ask for more information about this hair grass.  And who can blame us?  This lovely grass forms large clumps that resemble long, fine, shining blonde hair.  It's a beautiful plant that is really popular in Tennessee landscaping.

My new favorite Stipa
However, in Kew's grass garden, Mexican hair grass doesn't stand out from the rest.  It sort of blends into the mass of lovely clumps of grasses.  However, one of its cousins shines out from the mounds of Miscanthus and drew my interest from day one -- Stipa ichu (2006-491, ), the Peruvian feather grass.  What's the difference?  Where S. tenuissima resembles a short mass of shining blonde hair, S. ichu looks like a much taller swathe of shimmering silver hair.  Let me put it this way -- the makers of the Harry Potter movies could have used an infloresence of S. ichu to represent unicorn hair in their magic wands, and nobody would have questioned it.

It looks like unicorn hair

Compare the open panicles (left) to
the more silvery, young flower (right)
At Kew, the silvery panicles burst from the fine, green base towards the end of June.  They really shimmer in the morning sun.  These infloresences begin to open and fluff out through July, losing a bit of the silver and becoming more white and a little less reflective.  The open panicles are much lighter, and they get caught up in the wind much more easily.  It's really something to see this plant on a breezy day.  The clumps look like they're dancing with each other.

The silky flowers can also be tawny, white, or purple, and they can grow over a foot tall.  These flowers are held on a plant that could ultimately get 4 feet tall.  The base of the plant is a clump of fine, sturdy, green foliage (Hitchcock, 398).

Native to the Americas

As with its cousin, S. ichu covers a large range over North and South America.  You may find this silvery hair grass in the hills of Mexico, in the plains of Argentina, and even growing up in the heights of the Andes mountains.  In Hitchcock's monograph of the grasses of South America, he noted that S. ichu was fairly common in the upper altitudes of the Andes.  In the introduction, he described the area:

"Most of the region is mountainous, the Andes transversing it from north to south.  Although lying under the Equator, much of the region is so high an elevation that many ranges and peaks are capped with perpetual snow." (Hitchcock, 6)

S. ichu was first botanically described in 1798 from Peru as Javara ichu.  Traditionally Peruvians used "ichu grass" for thatching their homes and other structures (Hitchcock, 398).  The fact that this plant will thrive in the warm, dry, arid plains of Mexico up to snowy peaks m Peru means that it is tough and adaptable.  There is no indication that this plant is in danger of extinction in its natural habitat today, either from the CITES database or the IUCN Red List of threatened species.

Landscape value

This attractive and adaptable
ornamental grass deserves
a spot in any landscape
This is definitely an interesting, eye catching plant that deserves a spot in your garden.  When a group of plant sciences and landscape architecture students from the University of Tennessee came to visit Kew last week, two separately and independently mentioned this plant to me in conversation.  One student said that he couldn't capture the beauty of the grass garden in a photo, so he took some video as well.  I encountered the same problem when trying to get a good photo of S. ichu, so there is a video at the bottom of this post as well.

If you're growing at home, you'll want to give this plant a bit of space.  When planted in an area that is exposed to wind, it kind of whips around and could knock into its neighbors (see video).  Although this silvery grass would make an interesting focal point, it would really shine out en masse.  Consider planting Ajuga 'Black Scallops' as a neighboring ground cover to serve as as a dark foil to this shimmering Stipa.

If you have any questions, comments or suggestions, please feel welcome to leave a comment or send me an email.

To see more photos from this week, be sure to check out the album "They should call it 'unicorn hair grass'" on the Plante on Plants Facebook page.  "Likes", shares and comments are appreciated.

This eye catching grass really stands out from the crowd

All photos and videos were taken by Amanda Plante at the Royal Botanic Gardens, Kew unless otherwise stated in the caption.


Friday, August 1, 2014

These flowers look like Princess Jasmine's slippers

There are pretty flowers, there are beautiful flowers, and there are magnificent flowers.  This post is about a magnificent flower - jade vine, or Strongylodon macrobotrys (1963-72801).

"Eye catching" doesn't do it justice

The showy blooms of jade vine
are definitely worth making a trip
to a larger botanic garden to see
Like I said, the flowers are the feature that first caught my eye.  My co-hort Nathan and I had spent hours exploring the Fairchild Tropical Botanic Garden in the sweltering Miami heat.  Towards the end of the adventure, just as my enthusiasm was waning, I saw a glimmer of jade from a pergola in the distance.  My slow, tired trudge transformed into a quick step as I hastened to the tropical vine pergola.

The whole structure was draped with these really spectacular teal racemes.  Apparently each floral spray can grow to around 4 feet!  The individual blossoms that adorn each raceme look like they could be shoes for a Princess Jasmine doll.  They're violently teal, just like the Disney princess' outfit in Aladdin. Although the flowers are borne on a long raceme, they're not very large.  A flower may be about 6 cm in length.

And this isn't necessarily a brief show of blossoms.  According to the manual Flowering Plants and Ferns of Mt. Makiling, the jade vine will flower from January to June, and again from November to December in its natural habitat.  That's quite a long blooming period!

Gargantuan fruits

Given the somewhat dainty nature of the flowers ("dainty" is not the right word, but I can't think of a better one), I was absolutely floored by the massive size of the fruits when I first saw them in Kew's Princess of Wales Conservatory.  They're like mangoes!  Is it any surprise that out of all the fiddly flowers that bloom, only one or two fruits develop? 

The showy blooms of jade vine
are definitely worth making a trip
to a larger botanic garden to see
In the wild, Strongylodon are pollinated by bats.  That's not feasible for plants grown in conservatories, such as Kew's Princess of Wales or Palm House.  However, rather than forgoing hope for developing these huge fruits, Kew practices hand pollination.  When Nick from Kew was giving the interns a tour of the Princess of Wales Conservatory, I asked about the contents of his tool belt.  Sure enough, he had a small paintbrush that he uses to pollinate flowers like the jade vine. 

Fun fact -- you can actually track some of the maintenance details of specific plants in Kew's living collections database.  This exact plant was successfully hand pollinated by Simon Creed in 2013.  Simon pollinated the flowers at the end of March, and the seed was ready for collection the first week of May that year.  For those of you who haven't been following NEW at Kew, Simon is a young horticulturalist who just graduated from Kew's apprenticeship program on Friday.  Congratulations Simon!

If you've only seen the flowers, it's worth making a second visit to see this plant in fruit.  Depending on various factors, there should be fruit around this time of year.  In its native range, jade vine fruits in May and September.  It doesn't seem to follow that set schedule in cultivation.  Kew's specimen has some large fruits right now.

Is it from outer space?

The fruits are really something to
marvel at as well
I have trouble wrapping my head around the idea that these splendiferous flowers are naturally occurring someplace on this planet.  However this species is native to the Luzon and Mindoro islands in the Phillipines.  You'll find their teal blooms draped from vines that are clinging to the steep slopes of Mt. Makling, up to 1,000 meters up in altitude.  This mountain is actually a volcanic mountain, although it hasn't erupted in recorded history, or at least since the 16th century.  The mountain rises from the Laguna de Bay on Luzon Island.

As you may have read in the previous few posts, this plant is not listed as endangered or threatened by the CITES database or IUCN red list.  However, Kew's living collection database states that this species was on the IUCN red list of endangered species in 1997.  I wonder whether this plant has made a recovery in the wild, or if there is a problem with their website.

Appreciating this plant

This is not a small plant.  Unless you
live in a tropical climate, it would
be best to appreciate at a botanic garden.
This tropical plant has a USDA hardiness zone rating of 10 to 11.  This means that unless you live in a tropical climate like Miami, it isn't really feasible to grow Strongylodon as a landscape plant.  Some enthusiasts may be tempted to grow as an interior plant, but that wouldn't be practical either.  Remember, the jade vine is native to the warm, humid cliff faces and river banks of the Philippines.  If your house isn't tropical, this plant won't be happy to grow there.  Also, it would just be too big to keep inside. 

Rather than growing at home, I recommend interested parties to visit a botanic garden that has a conservatory.  If you live in a small city, your local public garden may not have this plant (or a conservatory), but seeing this plant in bloom makes the journey to a large garden, like Kew,  Fairchild or Missouri Botanic, totally worthwhile.  Check with the garden first to make sure that it is in flower or fruit.  I can attest that seeing this magnificent plant in full bloom is worth the trip!

If you have any questions, comments or suggestions, please feel welcome to leave a comment or send me an email.

To see more photos from this week, be sure to check out the album "A Whole New World with Jade Vine" on the Plante on Plants Facebook page.  "Likes", shares and comments are appreciated.

All photos and videos were taken by Amanda Plante at the Royal Botanic Gardens, Kew unless otherwise stated in the caption.

  • Center for the International Trade in Endangered Species database
  • Fernandon, E.S.; Sun, B.Y.; Suh, M.H.; Kong, H.Y.; Koh, H.S. (2005).  Flowering Plants and Ferns of Mt Makiling.
  • Kew's Living Collections database
  • Pancho, J.V. (1983).  Vascular Flora of Mountain Makiling and Vicinity (Luzon: Philippines) part 2.
  • The International Union for Conservation of Nature and Natural Resources Red List of threatened species
  • The Plant List website
  • The Royal Botanic Gardens, Kew website and staff

Monday, July 21, 2014

The flower that makes me crave fried eggs

The 4 inch flowers of Romneya
 look like a fried egg
cooked sunny-side up
Believe it or not, I actually had a very difficult time picking a plant to cover this week.  I knew that somewhere in Kew's 300 acres I should be able to find one plant that I find genuinely interesting, but inspiration never struck.  My group spent a couple days working in the Secluded Garden this week, and while we were working I kept running through plants in my mind, nixing some and earmarking others for later.

While I toiled away in mental anguish, visitors kept interrupting my train of thought to ask, "Excuse me please, what is the name of that plant?"  "What is that plant?"  "What do you call that plant?  That one on the other side of the water?"  Each group was asking about the same plant -- a large, shrubby poppy that was covered in white blooms growing just on the other side of the stream (1994-3738, SCON).  Nobody could seem to remember the genus, so every time someone would have to scurry down the embankment, ford the waters, and call back, "Romneya coulteri -- It's a kind of a poppy."

Finally, after four or five times, I thought to myself, "This may be a plant worth writing about."  And I wasn't disappointed.

Back to its roots

Romneya coulteri, or the canyon matilija poppy, is native to southern California.  Its range includes Los Angeles, Riverside, Ontario, and San Diego counties.  R. coulteri is perennial from USDA hardiness zones 7 to 11.  It thrives in chaparral and coastal shrub habitats -- especially in dry washes and canyons where the altitude is less than 1,200 meters (Hickman, 816). 

Seed head of R. coulteri.  The seeds of
this species of poppy actually
have a higher germination rate when
exposed to smoke caused by a fire
The matilija poppy may also be spotted in areas that have been affected by fire.  R. coulteri has adapted to fire damage in two ways.  First, shoots will easily re-sprout from the roots after the plant is burnt to the ground.  Second, exposure to smoke can actually increase seed germination (California, 239). 

This California native was first noted by a European in Baja during the early 1800's.  T. Romney Robinson was an Irish astronomer who had an eye for beauty in the sky and on the ground.  The genus was named Romneya in recognition of his discovery (Hickman, 816).

Today, the habitat of R. coulteri is threatened by urbanization, including new home and shop developments, roadside expansion, and flood control (California, 239). Both Kew's living collection database and the California Native Plant Society note that this is a rare plant in need of conservation.  The notes in Kew's database for both of their specimens of R. coulteri indicate that in 1997 this species was listed as endangered by the IUCN red list.  However, neither the CITES database nor the IUCN red list currently list it as endangered.

It looks like a fried egg

Just like all of our curious visitors, the feature of this plant that really stands out to me are the white and yellow blossoms.  Their 4 inch blooms look just like a fried egg cooked sunny-side up.  This species actually produces the largest flowers out of any of California's native plants.  That is especially compelling when you consider that the state of California is over 400,000 square kilometers and covers twenty-one distinct (and often wildly different) types of landscapes.

R. coulteri in the Papaveraceae section of the
Chelsea Physic Garden.  Notice how much taller
it is than the other poppies in the bed.
R. coulteri in cultivation is really floriferous.  I saw two specimens of the matilija poppy at Kew (2004-2746, PERH) and one at the Chelsea Physic Garden, and they were all totally laden with flowers. You can count on this plant flowering non-stop through the whole summer, from as early as May right up until the end of July.  The foliage is a very attractive soft, silvery blue.  Although the leaves vary in length, the deep lobes and cool color really softens the effect of the sunny blooms.

If you're picturing these flowers held on a plant that resembles other poppies, think again.  This is a big plant -- another common name for R. coulteri is tree poppy.  It isn't uncommon for the matilija poppy to grow upwards of 6 feet (2 meters) tall.  I haven't read anything on this, but I'd be interested to learn whether the plant sets flower buds on old or new growth.  This would dictate how you should prune to maintain size.  If it sets flowers on old growth, then all old stems that have already bloomed should be removed at the end of the growing season.  If it blooms on new wood, then it should be cut back hard to about 6 inches after the danger of frost has passed in the spring.  Or you could embrace this plant at its natural height and site accordingly.

Landscape value

Although the matilija poppy is native
to dry and sunny southern
California, it thrives in more cool,
moist and shady conditions
Although R. coulteri is native to a hot, dry Mediterranean type of climate, the plant is very adaptable in cultivation.  There's a specimen at Kew that is absolutely thriving in afternoon shade and relatively rich soil.  However, the matilija poppy may be more vigorous in environments that are similar to its native habitat, including the Mediterranean and areas in Africa, Australia, and so on.  It has been described as having weedy tendencies in southern California, so gardeners in similar climates have a responsibility to keep an eye on their specimens and report any invasive qualities.

The matilija poppy is at home towards the back of the flower border, where it is less likely to cover up smaller growing companions.  This plant doesn't have a lot of winter interest, so consider siting next to an evergreen, an ornamental grass, or a tree with interesting bark.  I think this plant would be the perfect fit for growing beneath a kitchen window.  The sunny blooms would really brighten the view and give a friendly reminder to enjoy a fried egg sunny-side up once in a while.

If you have any questions, comments or suggestions, please feel welcome to leave a comment or send me an email.

To see more photos from this week, be sure to check out the album "The flower that makes me crave fried eggs" on the Plante on Plants Facebook page.  "Likes", shares and comments are appreciated.

Pistil and stamen of Romneya coulteri
This poppy is sure to stand out in any landscape.  Notice how prominent the flowers are surrounded by the other colorful selections in Kew's Duke's Garden.
All photos and videos were taken by Amanda Plante at the Royal Botanic Gardens, Kew unless otherwise stated in the caption.

  • (1994).  California Native Plant Society's Inventory of Rare and Endangered Vascular Plants of Califoria (5th ed.).  CNPS Special Publication, p. 239
  • Center for the International Trade in Endangered Species database
  • Dave's Garden Plant Files
  • Hickman, J.C.  (1993).  The Jepson Manual: Higher Plants of California (3rd printing). Berkley, CA: University of California Press, p. 816-817.
  • Kew's Living Collections database
  • Rundel, P.W. & Gustafson, R.  (2005).  California Natural History Guides Introduction to the Plant Life of Southern California: Coast to Foothills. Berkley, CA: University of California Press, p. 101-102
  • The International Union for Conservation of Nature and Natural Resources Red List of threatened species
  • The Plant List website
  • The Royal Botanic Gardens, Kew website and staff

Sunday, July 13, 2014

If you like pineapple lilies, you'll love Eucomis vandermerwei

Eucomis vandermerwei is currently
on display in Kew's Alpine House.
I love the purple spotted foliage!
When I first laid my eyes on a pineapple lily (Eucomis), it was love at first sight.  The bold foliage, the unique flower, and the really striking growth habit all do something for me.  My first experience was when Dr. Susan Hamilton had me do a mass planting of Eucomis comosa 'Sparkling Burgundy' in the back 40 of the University of Tennessee Gardens.  If I recall correctly, we had a little more than a dozen 3 inch pots left over from a plant sale, and we needed to find a home for them in the gardens.  The last time I strolled through the area, they were still there, bold and bright as could be.  In most gardens, pineapple lilies are usually planted singly as a focal point or foil, but en masse they're really something to shout about.

Last week, the interns at Kew were given a tour of the Alpine House, and I was head over heels all over again -- this time with Eucomis vandermerwei (2011-1894, RDRE).

It looks like a pineapple

This pineapple lily is unlike any other I've ever seen.  It has really attractive purple and green spotted foliage, and the leaves are a bit more strappy than the other species that I've seen before. Although it is given the common name because its flower looks a bit like a pineapple, the habit and foliage reminds me of pineapple plant too.

Both the common name and the scientific name describe the plant's unusual flower.  Eucomis is derived from the Greek meaning something like beautiful hair in a "top knot" style (Pearse, 38).

Native Range

In Mountain splendour: Wild flowers of the Drakensberg, Reginald Pearse describes the Eucomis as, "Essentially an African genus."  He goes on to write that most pineapple lilies harken from South Africa, many in the Natal region.  Wakehurst's specimen of E. vandermerwei was collected from the just north of the Natal in the Mpumalanga province.  Kew's live collections database notes that this plant was on the IUCN Red List as an endangered species in 1997.  Apparently it has made a comeback since then, as it is no longer listed.

This plant's common name is pineapple
lily, because the flower resembles that fruit.
The genus Eucomis refers to how the flower
resembles a beautiful "top knot" hairdo.
Unlike the other Eucomis that flourish in the grassy gullies of the coastal region, E. vandermerwei is an alpine plant.  In the wild, you will find this species in the rocky savannah on a high plateau.  This means that E. vandermerwei can survive winter frosts (USDA hardiness zones 6a - 8b).  However, the problem with cultivating this species in a North American or European garden doesn't stem from cold hardiness. 

When I saw this plant for sale this weekend at the Hampton Court Palace Flower Show, I decided to ask the vendor from Cornwall's Trecanna Nursery for some cultivation tips.  He told me the main reason why gardeners struggle to grow this plant is because of its water needs.  Although its native habitat does receive a fair amount of rainfall (one source lists about 24 inches or 640 mm annually), most of this occurs in the summer.  "I tell people to keep it in a pot and move it inside in the winter so it can dry out,"the nurseryman advised.

Landscape Value

If you live in an area that is similar to E. vandermerwei's native range, then I think that a clump of this plant would be a real show stopper.  If you're like me, and live in a place that has soggy winters, then it would be best to reserve yourself to one specimen in a container so that it will be easier to accommodate its finicky water needs.  

Although I'm sure it that combining this plant with a limey annual like a sweet potato vine, 'Rita's Gold' Boston fern, or 'Lime Zinger' elephant's ear would really bring out the unique foliage, make sure that you keep an eye on soil moisture.  This should be okay because it receives quite a lot of rainfall in the warm months in its native habitat.

Industry Value
Keep your eyes peeled for
the 'Tiny Piny' series!
The average gardener will have a difficult time finding this species if it isn't carried in their local nursery.  To learn more about the challenges and merits of growing this plant in on the industry side of horticulture, I interviewed Eddie Walsh, prominent Eucomis breeder and owner of New Zealand's Starter Plants Co.  Mr. Walsh has actually been breeding Eucomis for the past twenty years!

Although Walsh has used E. vandermerwei to create colorful hybrids, there are some challenges to nurserymen who want to grow the straight species.  "One fault we see with E. vandermerei," he explained, "is the leaves are very long and not desired by potted plant growers as they are difficult to pack and take up more bench space."  However, many of the new Eucomis hybrids that Walsh and his colleague Ian Duncalf have developed have actually been bred, in part, to address this problem.  There are some really worthwhile "minis" that have the interesting characteristics of E. vandermerwei, but are more compact for growers.

Floral display at the Hampton Court Flower Show.
One challenge to Eucomis breeders is trying to
pinpoint features that will be desirable
to consumers 9 years in the future.
Another problem is that all Eucomis species are native to the southern hemisphere.  For those who many not know, when it is summer in the northern hemisphere, it is winter in the south and vice-versa.  This means that if live plants are shipped to North America or Europe, they will struggle to adapt to our seasons.  Walsh and Duncalf handled this challenge in a really interesting way -- he sends his bulbs to India to propagate into mini-bulbs.  These new bulbs are then sent to a grower in the state of Washington who prepares them for the U.S. Market.

According to Walsh, the biggest problem with breeding pineapple lilies is that, like with many bulbs, the amount of time required. "It takes about 9 years from making a cross to having a variety ready in quantity for the market," he explained. "Who knows what colors they will want that far ahead?"

To the home gardeners reading this, keep your eyes peeled for some really adorable new "tiny piny" pineapple lilies.  Walsh informed me that the UT Gardens in Jackson are currently trialing this series, so stay tuned to their annual trials website to see how they perform in that region.  Be sure to talk to your local retail garden center or plant nursery if they don't already have these plants in stock.

If you have any questions, comments or suggestions, please feel welcome to leave a comment or send me an email.

To see more photos from this week, be sure to check out the album "If you like pineapple lilies..." on the Plante on Plants Facebook page.  "Likes", shares and comments are appreciated.

Trecanna Nursery's eye catching display of Eucomis and Crocosmia at the 2014 RHS Hampton Court Palace Flower Show.  Both of these genera are native to South Africa.

All photos and videos were taken by Amanda Plante at the Royal Botanic Gardens, Kew unless otherwise stated in the caption.


Sunday, July 6, 2014

Add Impact (Literally) to Your Garden with the Exploding Cucumber, Ecballium elaterium

Echballium elaterium is in the
cucumber family, so it's not surprising
that the fruits look like little cukes
One this week's tasks at Kew was to prop up and cut back plants that were flopping into the grass paths of the Order Beds.  We were working under the guidance of Chrissy, one of Kew's horticulture students.  We walked through some of the lower beds, and she identified sections that needed to be propped and other plants that needed to be trimmed.  She warned me, "Watch out for the squirting cucumber."

Having just learned that one of the plants in the Cucurbitaceae beds squirted, and knowing full well what a cucumber looks like, I set off to work.  But by the time I had made my way down toward the end of the section, about twenty or so minutes later, I had already forgotten Chrissy's warning.  With the first snip of my secateurs (pruners), a small cucumber shot out from the foliage it had been hiding under and hit me square in the stomach.  Startled, I dropped my pruners and fell backwards, off of my knees and flat onto my rear.  I thought, "That's a plant worth writing about."

Mediterranean Roots
The exploding cucumber, also known as Ecballium elaterium (1790-624, UCNW), is native to the Mediterranean region.  As is true with many Mediterranean natives, this plant prefers well drained (but not dry) soil in a sunny location.  However, E. elaterium is adaptable and can handle less than ideal conditions.  Although this plant is a perennial in its native region, it is grown as an annual in cooler climates like England and much of North America (USDA hardiness zones 8b to 10a).

Flower bud, opening bloom, and
finished flower head of E. elaterium
The E. elaterium has been used medicinally since the time of the ancient Greeks.  One of the first written records of this plant is by Hippocrates (460 - 375 BC), who described how to prepare various parts of the plants to cause purging in patients.  The specific epithet elaterium is actually derived from the Greek "elaterio" which means "to cast out".  This probably has more to do with the fact that the plant shoot its seeds out up to 6 feet (see video below) rather than its medicinal use for purging and reducing fluid retention.

There is no indication that this plant is in danger of extinction in its natural habitat today, either from the CITES database or the IUCN Red List of threatened species.

Botanical Description
E. elaterium was first described in 1824 by Achille Richard, French botanist, doctor, and director of the Benjamin Delessert Herbarium and at Paris' Muséum d'Histoire Naturelle.  Several online sources state that the plant is so toxic that a doctor suffered "serious symptoms" when transporting seeds of this plant inside of his hat, from the Jardins de Plantes to his home in Paris.  Perhaps that doctor was Achille Richard?

Anatomical Characteristics
E. elaterium has the same growth habit as a bush cucumber, although the vine does not produce tendrils.  The leaves, flowers, and fruits (to an extent) also look like those of a cucumber.  However, this plant should not be eaten like a cucumber, because it is poisonous.

The exploding cucumber makes a
nice, silvery groundcover that provides
a literal impact factor to any landscape
Although the fruits looks somewhat like little cucumbers, they are much smaller (about 2 inches in length) and contain fluid and seeds.  As the fruits develop, they become slightly pinched on one side, which increases the pressure inside.  When the stem and fruits begin to yellow, a small brush from an unwary animal or gardener will cause the fruit to shoot off of its stem, spraying fluid and seeds behind it.  If any seeds get stuck to the unfortunate (and probably very startled) soul that disturbed the plant in the first place, they may transport the plant's genetic material to a new place, where the exploding cucumber can start this process all over again.

Landscape Value
The exploding cucumber has really nice silvery, densely pubescent foliage and stems.  This ground cover would be good when contrasted with plants that have different forms and textures.  Perhaps in a large container with a bold, upright 'Sparkling Burgundy' pineapple lily (Eucomis comosa) and a fine, feathery 'Rita's Gold' Boston fern (Nephrolepsis exaltata).  E. elatarium should grow to drape over the edge of the container, showcasing its beautiful foliage and explosive fruits.

This plant has a lot of impact factor -- literally.  This would be a fun addition for a home landscape near walkways to startle unwitting guests.  However, use with care.  This plant is toxic.  So although it seems like the perfect, fun addition to a children's garden, it really should not be grown in that situation.  Children may confuse the fruits with actual cucumbers, eat them, and become very sick.

So if you're looking for a fun, adaptable annual to try in your garden this year, consider adding the exploding cucumber.  Remember to plant responsibly -- this plant shouldn't be grown where children can get a hold of the fruits and eat them, because they could become very sick.

If you have any questions, comments or suggestions, please feel welcome to leave a comment or send me an email.

To see more photos from this week, be sure to check out the album "Exploding Cucumber" on the Plante on Plants Facebook page.  "Likes", shares and comments are appreciated.

All photos and videos were taken by Amanda Plante at the Royal Botanic Gardens, Kew unless otherwise stated in the caption.


Sunday, June 29, 2014

Giants in the Conservatories, Victoria amazonica and cruziana

Introductory page to Twelve Views of
.  Note the V. amazonica in the
water. (Schomburgk, 1841)
Several years ago when I was just getting started in horticulture, I was flipping through a textbook and saw an old photo of a child standing on a massive lily pad.  The caption read something like, "Child supported by foliage of Victoria amazonica".  I thought to myself, "I'd like to see that."  And this week I finally did.

Kew currently cultivates two species of giant waterlily, both of which are in the waterlily family Nymphaceae.  Victoria amazonica (2007-1804, KKNO), formerly V. regia, grows in the Princess of Wales Conservatory and V. cruziana (2011-1436, HSIK) in the Waterlily House.

Discovery and Present Range

According to Ray Desmond in The History of the Royal Botanic Gardens Kew, V. amazonica was first seen by a European, a botanist for the Spanish government, in 1801 in Peru. Subsequently, botanists from France spotted the species in Argentina in 1828, a Germany botanist found it in the Amazon in 1832, and Robert Schomburgk found it on the River Berbice in British Guiana in 1837.  Schomburgk shared parts of the plant that he collected and drawings with John Lindley (who had an influential role in keeping Kew intact during a turbulent period in its history).  Lindley named the plant Victoria reggia after Queen Victoria (Desmond, p. 178).

Tom and Tiffany prune and remove flower buds from
V. amazonica in the Princess of Wales Conservatory

V. cruziana inhabits a similar region, with a range from Paraguay to Northwest Argentina.  Both of these massive waterlilies can be found today in South America near Bolivia.  Neither of these species have been assessed by the IUCN for any threats to their existence in the wild.  Furthermore, CITES did not list either Victoria in their endangered species database.  Although those organizations have not listed these as threatened species, the environment they are native to could be damaged by climate change and human development.

Cultivation at Kew

Victoria amazonica was first cultivated at Kew in 1846, when twenty five seeds were bought from a collector from Bolivia.  Only two of the seeds sprouted, but they died shortly afterwards.  The issue seemed to be how the seeds were transported from Bolivia to England.  The first shipment had been packed it clay, and the next two were packed in soil in a Wardian case, dry capsules.  A fourth shipment of seeds packed in clean river water that arrived in 1849 was more successful.  That season Kew was able to raise 50 plants in a large tank in one of the glasshouses.

Visitors from around the globe stop in the
Waterlily House to inspect V. cruziana
At that time, several gardens in the area were essentially competing to see who could coax the first flower.  While the specimens at Chatsworth and Syon house were blooming, Kew's attempts were unsuccessful, possibly due to the poor quality of the Thames River water.  The first Victoria amazonica bloomed at Kew in June 1850.

The popularity of the giant water lily inspired Kew's director at the time, William Hooker, to commission a new building to house and display these finicky plants.  They completed the structure, today known as the Waterlily House, in 1852.  However, V. amazonica did not thrive, and was moved to another house (Desmond, p. 179).  Today you can find V. cruziana growing there in its place (Desmond, p. 313).

It is interesting to note that the V. cruziana growing at Kew wasn't the original collection.  Kew lost all specimens of this plant during World War II.  At that time, the conservatory at the University of Helsinki was damaged during a bombing.  Helsinki's V. cruziana survived the attack, and the progeny were sent to Kew, where they have been cultivated in the Waterlily House since 1999 (Desmond, p. 358)

As is true of many plants, the foliage of Victoria unrolls as it opens.  The underside of both V. amazonica and V. cruziana is covered in sharp spines.  The prickly spines beneath the opening leaves gives a strange, otherworldly appearance to the new growth.  These spines help prevent the leaves from being eaten by hungry fish, which would negatively effect how the foliage functions.

Unfurling new growth of V. amazonica
You see, in addition to spines, there are also deep ribs underneath the massive lily pads.  These ribs hold air beneath the pad to keep it buoyant.  They also provide structural support, like the frame of a house.  Enough strength, at times, to support the weight of a small human.  So if a grazing fish were to nibble too much of the foliage, this would compromise the strength of the leaf and its ability to stay afloat.

Another interesting fact about Victoria leaves is that the foliage will grow to the size of the container.  When I asked Silke, who works in the Waterlily house about the feasibility for growing V. cruziana at home, she concluded that it would be possible, but difficult.  And if placed in the size pond that is regularly found in a home landscape, the foliage wouldn't be much larger than that of any other lily pad.

Although the leaves of V. cruziana
(above) are smaller than V. amazonica,
it has a much taller lip.
So what's the difference between the foliage of these two giants?  For one thing, V. amazonica tends to produce larger leaves.  The foliage of V. amazonica can reach 2.5 meters in diameter, while the diameter of V. cruziana's leaves usually maxes out closer to 2 meters.  But these statistics don't stop a little friendly competition between staff in the Waterlily House and the Princess of Wales Conservatory. 

This year, the staff competed to see who could produce the largest lily pad by a certain date. Silke in the Waterlily house told me that her group had lost the competition because they got a later start.  I asked Tom, an apprentice, and Tiffany, a staff member, in the Princess of Wales Conservatory about the wager.  Tom grinned and said, "Yeah, it wasn't even close."

Although the foliage of V. amazonica may grow larger than V. cruziana, the edge of the pad is not as tall.  While this may not seem that important at first, a tall edge is crucial to prevent other leaves that would compete for sunlight from sliding on top of the pad.  This lip can also be more aesthetically appealing.  It provides more of a reflection on the water, and is really lovely when the sunlight shines through.

Unopened V. amazonica flower bud, held by Tom, an
apprentice in Kew's Princess of Wales Conservatory
Both species have large, creamy white flowers that open in the evening and are pollinated by beetles. Even though both giant waterlilies are starting to set flower buds at Kew, you won't see any on display until later in the year.  When I arrived at the Princess of Wales Conservatory, Tiffany and Tom were pruning out the prickly buds to compost.  The reason why is that if allowed to flower, the plants' energy would go into flowering, fruiting, and setting seed rather than growing large leaves.  People come to Kew from all around the world to see these massive lily pads, so Kew does their best to produce big ones.

However, the species in cultivation at Kew are allowed to flower later in the year, because the seed is vital to producing the next season's crop.  Neither V. amazonica or V. cruziana will reliably overwinter at Kew, even if provided the best possible environment.  So, staff pollinate the flowers by hand, store the seeds in water, and start new seedlings early in the year and grow them on in the Tropical Nursery glasshouse so when they are ready to move they are large and ready for visitors.


Tom disects the unopened flower bud
of V. amazonica so we can inspect
the anatomical features
Although both species of Victoria thrive at Kew during the warmer months, both begin to decline in the fall.  This makes sense, because both plants are native to the tropics of South America.  For interested readers in the US, their USDA Hardiness Zones are 10-11.  For readers in the UK and beyond, that means they can tolerate a minimum temperature somewhere between 4 and 11 degrees Celsius.  Measures could be taken to overwinter the plants, but the effort would require very specialized environments with specific heat, supplemental light, and water requirements.  Instead, Kew treats these plants as annuals rather than temperennials.

In Kew's online profile of V. amazonica, they note that aphids can be a problem at times.  They try to reduce pest and disease pressures by keeping the plants healthy and happy by adding plenty of fertilizer, growing in a large enough pot, and regular pruning.

A Sight Worth Seeing

Before leaving the Princess of Wales Conservatory, I took a moment to stand back and take in one last look of those giant leaves.  An older gentleman had pushed his father in a wheelchair to the water's edge while I'd been speaking to Tiffany and Tom.  "What do you think of it?" I asked.  "I've never seen anything like it," the father responded. "Neither have I."
If you have any questions, comments or suggestions, please feel welcome to leave a comment or send me an email.

Victoria amazonica can be seen in Kew's Princess of Wales Conservatory
Kew's Victoria cruziana is on display in the Waterlily House
All photos were taken by Amanda Plante at the Royal Botanic Gardens, Kew unless otherwise stated in the caption.

  • Center for the International Trade in Endangered Species database
  • Desmond, Ray.  (2007).  The History of the Royal Botanic Gardens Kew (2nd Edition).  London: Kew Publishing, Royal Botanic Gardens, Kew.  177-179, 345-346.
  • Kew's Living Collections database
  • Missouri Botanic Gardens plant finder database
  • Perennial Resource glossary
  • The International Union for Conservation of Nature and Natural Resources Red List of threatened species
  • The Plant List website
  • The Royal Botanic Gardens, Kew website and staff
  • Schomburgk, Robert H. (1841).  Twelve views in the interior of Guiana from drawings executed by Mr. Charles Bentley, after sketches taken during the expedition carrier on in the years 1835 to 1839, under the direction of the Royal Geographical Society of London, and aided by Her Majesty's government with descriptive letter-press.  Retrieved from The New York Botanical Garden Mertz Digital Collections.