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.

 A bit after posting this plant profile, my new friend Ann in Australia sent some helpful information that I wanted to be sure to share with you.  Thanks for sharing Ann!

"I live in the Lower Blue Mountains west of Sydney, New South Wales, Australia.  We have very hot, dry but humid summers. (Heat zone 4, cold zone 10). Recently up to 46 C. I planted my Romneya about 10 years ago in my front garden,  in a dry westerly aspect  in full sun, on a slope with good drainage. It is tall (about 2 to 2.5metres high) with lanky canes and flowers on new growth which I cut back in late autumn to about 15cm. It will sucker by sending out underground rhizomes several metres away  and also sets seed once the plant is established. It has beautiful crepe paper thin wrinkled petals of pure white & a large raised centre of golden stamens heavily laden with pollen. The flowers measure roughly 15cm and the foliage is a smooth blue/grey. I don’t fertilise it & it relies solely on natural rainfall. The flowers are a constant delight to the bees and the shrub often “hums” with bee activity. People will often stop and ask me what this beautiful plant is when in flower."

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.