Aristolochia

I was giving my students a mid-term ID exam last Saturday, when we encountered this unusual vine, growing in the Livington Ripley gardens. 

The plant is Aristolochea gigantea, or Dutchman's pipe, a vine native to Brazil.  The flowers, as you can see, are amazing.  Large - almost 8" diameter, the flower consists of a red, velvety flat disc white venation.

A large bladder shaped chamber is attached to the disc with a small tube.  While the structure itself looks a lot like a carnivorous pitcher plant, like Nepenthes. 

But when we dissected the flower, the presence of any digesting fluids was nonexistent.  Instead, the tubular structure was covered with long, fine hairs.  I speculated the hairs were key in moving insects into the tube and to the flower at the base, and further guessed that the pollinator was some kind of scavenging insect, like a fly -- since the flower itself looked like rotting flesh.

Indeed, this plant is considered a carrion flower and is often pollinated by flies.  The hairs play a pivotal role -- they keep the flies trapped at the base of the capsule for several days.  The fly lives on nectar in the capsule until the pollen is released by the anthers, at which point the hairs drop down and the fly climbs out of the chamber.

Aristolochia is derivative from the ancient Greek words Aristo- which means 'best' and -lochia which means 'delivery'.  For a long time this plant was believed to be helpful in childbirth.  It's since been determined that this plant is actually quite dangerous to the kidneys.

Winter Aconite

Here's a small swath of winter aconite, or Eranthis hyemalis, growing near the Edgeworthia I posted about yesterday.   I love this sunny yellow flower, which grows from a tuber in the spring.  Leaves and blossoms emerge at the same time in early spring and when the forest canopy becomes more dense, the plant has adapted to lose its above-ground parts and become dormant. This phenomena, in regards to plants, is called aestivation.

Eranthis is in the Ranunculaceae or buttercup family.   The leaves are peltate, which means they don't have petioles.  To me, they look like the ruffled collars you'd see on a clown.

As cheery as this plant is, keep it the hell away from your belly.  It's infamously toxic, as it was what Medea used to poison Theseus.  It evidently tastes quite bad, so you'd be unlikely to actually digest it. Er- is ancient Greek for 'early' and -anthis of course means flower, so the plant is an early spring flower. 

Datura metel, and Botticelli

Posting yesterday's pic of the stone bench in Giverny made me a bit wistful for Paris and so I began browsing some of my photos.  I realized I had not yet blogged about Datura metel, an annual I photographed at the Jardin du Plantes. 

 Datura is a lovely annual, reaching about 3' high and at the gardens here it's mixed with Verbena bonariensis.  However, it is dreadfully toxic when ingested.

Most species of Datura are toxic and recently when art historian David Bellingham hypothesized that  D. stramonium is featured in Botticelli's Venus and Mars.   He noted a strange fruit in the hands of an imp surrounding Mars and had it identified by a botanist at Kew Gardens as Datura.
 

The story at NPR on this is terrific - as it elaborates on the plants toxicology and touches on the debate about whether or not Datura stramonium could have possibly been cultivated in Italy during Botticelli's time (there's some speculation on whether or not the plant is native to the new world and India, or only the new world). 

Taxus baccata

Similar to yesterday's post on Tsuga, today's post on Taxus is much-overdue.  The specimen below (taken at Longwood) is Taxus baccata or English yew.  

When it comes to yews, I'm not really sure where to begin.  They are however, truly misrepresented here in the states.  The specimen photographed for this post is lovely and no doubt it's well over 100 years old, but that's hardly significant when you compare it to the famous specimens in England which are estimated to be 3000-4000 years old.  One of the more famous yews is the one in Llangernyw, which has a circumference of 47'.  Dirr writes lovingly of his experience near a 3000 year old specimen in Dundonnell, Scotland: For a brief moment one could imagine the gathering of the clans, the wailing of the bag pipes and the call to battle.

I remember working at a plant nursery in high school and at that point, my only exposure to yews was their prolific use on college campuses as hedges or in soulless foundation plantings around strip malls and fast food joints.  I remember having difficulty reconciling those images of yews with Thomas Hardy's Tess of the D'Urbervilles, where the plants were referenced as such:

It was somewhat disguised from the road in passing it by yews and evergreen oaks, but it was visible enough up here. 

And later:

Darkness and silence ruled everywhere around.  Above them rose the primeval yews and oaks of The Chase, in which were poised gentle roosting birds in their last nap; and about them stole the hopping rabbits and hares.

In short: to really, truly appreciate this plant, go to England.

Back to our American specimen.  The bark on a mature yew tree is rich in tones of cinnamon, brown and green and the bark has a shaggy, exfoliating quality.  When in partial shade, the leaves appear in two ranks along the stem.  Red fruits appear on the plant in late summer/fall.  The fruits are the only parts of this species that are not highly toxic.  (That's because the seed is toxic and our stomachs aren't capable of digesting it enough so that the poison is released.)  All other parts of the plant are quite dangerous.

In addition to the large spreading trees that Taxus baccata can become, they are also regularly used for topiary.  Yew topiary is far more common in Europe but Longwood does have a serviceable garden showing the possibilities. 

Finally, one can't talk about yews without mentioning that they are like chocolate-coated crack cocaine to deer.  If you have even a whiff of a deer presence in your area, do not bother using any species of Taxus as they will quickly be devoured.

Tsuga canadensis

It's high time I post an entry on one of my favorite evergreen trees, Tsuga canadensis or Canadian hemlock.  The allée below was taken at Longwood Gardens, not far from the entry. 

 

I love the willowy nature of hemlocks -- some coniferous trees like spruce can seem so rigid and stiff - but hemlocks have a softness to them that is unique.  It's also native to the mountainside forests of this region which adds to the plant's advantages.

 

The short, flattened dark green leaves are easy to identify if you look for the white stomatal stripe that appears on the underside.  The leaves are generally arranged in two ranks along the stem, with a third, smaller leaf compressed on top of the stem.  The cones are small - smaller than a ping pong ball. 

In the image above, you more clearly can see the shorter, third leaf.  You will also notice that this leaf appears "upside down" -- that is, the side with the stomatal stripe is facing up.  You also have probably identified the evidence of wooly adelgid on the branches.  The white, cottony substance on the stems are egg sacs of the pest.  Wooly adelgid was introduced to the US in the Pacific Northwest in 1924.  It's estimated to have reached the Middle Atlantic states by the 1950's.  Tsuga is the pest's food of choice and over the years, hemlocks will eventually die from an infestation.  Until then, they will appear grayish in color, as the insect has sucked most of the sugar-rich chlorophyll from the leaves. 

The specimen above is a weeping cultivar of hemlock.  The most famous weeping cultivar is called 'Sargentii.'  These are extremely slow growing (read: expensive) plants and in my opinion, they're somewhat strange-looking.  Of course, my students already know that I have a bit of a bias against dwarf or weeping conifers. 

Finally, Tsuga is not the genus that Socrates purportedly died by.  That plant is called poison hemlock or Conium maculatum.  The common name hemlock was applied to Tsuga because, as legend has it, early settlers thought the crushed leaves of Tsuga smelled like Conium.

Prickly Alyxia (Alyxia ruscifolia)

Here in Australia it’s spring and I have chosen an often overlooked plant, the Prickly Alyxia or Chain Fruit (Alyxia ruscifolia) a member of the Dogbane family Apocynaceae, as the theme.

Commonly found growing as an erect shrub of around two or three meters tall in the understorey of many of the rainforest types in the high rainfall areas that stretch from southern New South Wales to New Guinea; and from sea level to the mountain ranges.

As a general rule plants in this family exude a milky sap if bruised and many species are poisonous if ingested.  The sap is one of the defence mechanisms, which in effect deters herbivores from feeding on the plant.  Apparently the common family name refers to the plant's toxic nature and which has been described as poisonous to dogs.  Derived from the Greek words where apo means ‘away’ and cyno refers to ‘dog.’  The family includes many garden ornamentals such as Golden Bell (Allamanda), Periwinkle (Vinca), Oleander (Nerium), Yellow oleander (Thevetia) and Frangipani (Plumeria).

Alyxia ruscifolia also produces milky latex if any part is broken.  One unique feature is the foliage, with shiny stiff leaves that can be arranged oppositely or in whorls of from three to six.  The leaves are usually not toothed around the edges but have a very sharp pointed tip, hence the term ‘prickly.’  Another interesting aspect is the arrangement of the fruit, a drupe, which may come singly, in pairs or other numbers as an orange/reddish chain; thus ‘chain fruit’.  The plants may be pruned and shaped; and perhaps used as a hedge, or a prickly deterrent along the border of your property.

In the evening, the small white flowers, which besides reflecting the limited amount of light available, also emit the sweetest of perfumes.  By these means the Prickly Alyxia attracts night flying insects for pollination; and as a bonus enhances the surrounding environment for us to enjoy.

For those who enjoy a nightly dose of the sweet taste of spring then the Prickly Alyxia is a must have for the garden.

Bougainvillea

Today I finally delved into some much-overdue photo management.  I'm not sure how many of you are mac users, but I always struggle with iPhoto.  It's fantastically convenient for uploading photos to the computer from your phone, but I can't quite seem to find a good system for organizing them.  I was getting lazy about placing pics in the right folder and too often the folder name just wasn't generic enough.  Today I threw out all my albums and resorted from scratch.  I used only the following labels: people, places, plants, projects.  

This pic below went into three of those folders.  This is a cultivar of Bougainvillea growing at a plant nursery in Waimanalo, Oahu.  I was photographing it to discuss its use on the project in Hawaii.  (Places, projects, plants).  

When I returned from Hawaii after my most recent August site visit I had every intention of *immediately* blogging about Bougainvillea.  Primarily because it was one of the first plants that had every caused me actual physical harm.  You see, depending on the variety, Bougainvillea can have modest or horrifyingly big thorns.  One of the plants I was handling was of the latter category.  My right index finger got pierced pretty badly by one of the thorns my last day on the site.  At the time, it just felt like a splinter, nothing to worry about.  But the next day I called Honolulu poison control, after waking with a finger that was swollen to about twice its usual size!  I was told to take some benadryl and see if it got better as the day progressed.  I did just that, and tried to ignore the horror stories I had stupidly read online. 

I am happy to say that my finger is just fine - it seemed to get back to normal after about two days.  And despite this medical hiccup, I am still a fan of the plant.  Bougainvilleas were discovered Brazil in the late 18th Century during a voyage captained by Louis Antoine de Bougaiville.  Their hardy habit and their ability to mutate quite easily has led this plant to be a popular favorite in any tropical or warm-Mediterranean climate.  The flowers are generally pink, red or purple, though white hues exist as well.  The pic above was taken at the nursery so the various designers on my Hawaii project could confer on the best shade of pinkish-red for the site in question.

You notice above that the showy part of the flower - the papery pink "petals" are actually bracts.  The true flower is small and white.