Botanical prints of threatened flora

For those of us who find beauty in plant forms, the botanical illustrations available online are an always-blooming visual pleasure. Here are two that came my way via a mention in today’s Botany Photo of the Day.

First, a gallery of members’ works on the site of the The American Society of Botanical Artists, well worth a visit. There are only a couple of examples for each artist, but you can follow links to websites for many of those represented.

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Detail, Mountain lilac or Greenbark ceanothus (Ceanothus spinosus), watercolor © Chris Chapman. Source [this is a frames page, click on artist’s name in list at side].

Also, the ASBA has made available online nearly all of a touring exhibition called Losing Paradise? Endangered Plants Here and Around the World.The exhibit is at The New York Botanical Garden through July 25 2010, and at the Smithsonian’s National Museum of Natural History in DC, August 14th through December 10th.

This ASBA blog has about thirty of the 44 artworks featured in the exhibition (another is added every few days), and each is accompanied by the text from the exhibit catalog: a description of the plant and its situation, and commentary from the artist. (Elsewhere, the ASBA also plans to post all 125 pieces that were submitted for the exhibit, with shorter text; only about a dozen are up now.)

Here are a few samples from the blog. The images on the page are thumbnails, be sure to look at the much larger versions.

PaintedTrillium.jpg

Detail of Painted trillium (Trillium undulatum), mixed media, © Anne Marie Carney, US.

Silene_regia.jpg

Detail of Royal catchfly (Silene regia), watercolor © Heeyoung Kim, US.

A perennial wildflower of the US Midwest; its bright red flowers are pollinated by butterflies and hummingbirds.

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Detail, Marsh gentian (Gentiana pneumonanthe), watercolor © Gillian Barlow, UK.

Marsh gentian is being studied all over northern Europe, mainly because of its fascinating relationship with the rare Alcon blue butterfly (Phengaris alcon). Adult Alcon blues lay their eggs on the outside of marsh gentian flowers, and when the larvae hatch, they emerge inside, where they begin to feed on the flower. After molting 3 times, these caterpillars chew through to the outside of the flower, then lower themselves to the ground on a “silken thread”. The caterpillar awaits the arrival of a Myrmica ant, which adopts it and carries it back to the ant’s nest. There it is fed by the ant colony through the fall and winter, growing quite large. In spring it forms a chrysalis, then emerges and exits the colony as quickly as it can to avoid being killed by the ants.

Actually, it’s even odder than that…

The larvae emit surface chemicals (allomones) that closely match those of ant larvae, causing the ants to carry the Alcon larvae into their nests and place them in their brood chambers, where they are fed by worker ants and where they devour ant larvae.

When the Alcon larva is fully developed it pupates. Once the adult hatches it must run the gauntlet of escaping. The ants recognise the butterfly to be an intruder, but when they go to attack it with their jaws they can’t grab anything substantial as the newly emerged adult butterfly is thickly clothed in loosely attached scales.

Over time, some ant colonies that are parasitized in this manner will slightly change their larva chemicals as a defense, leading to an evolutionary “arms race” between the two species.

The Phengaris alcon larvae are sought underground by the Ichneumon eumerus wasp. On detecting a P. alcon larva the wasp enters the nest and sprays a pheromone that causes the ants to attack each other. In the resulting confusion the wasp locates the butterfly larva and injects it with its eggs. On pupation, the wasp eggs hatch and consume the chrysalis from the inside. [Wikipedia]

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Alcon blue butterfly (Phengaris alcon). Source.

Since the butterfly lays its eggs right on the flower, it may be serving the gentian as a pollinator, if it visits more than one plant.

Below, the Santa Cruz Cypress.

Santa_Cruz_Cypress.jpg

The endangered Santa Cruz Cypress, Cupressus abramsiana, is found only in the coastal Santa Cruz Mountains of central California, where it grows in gravelly, sandy soils above the fog belt, with chaparral and other evergreen species. This tree, once abundant, succumbed over the years to vineyard and home development, and road building. Only five populations totaling a few thousand individuals remain, all within a 15-mile stretch of the coast. It was Federally listed in 1987. It is still threatened by competition with non-native plants such as pampas grass and French broom, insect infestation and hybridization with other cypress species.

Visit the ASBA blogspot to see the rest of 30 or so. The catalog of the exhibit, from which these texts are excerpted, is on sale for $29.95 + s & h.

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