Monday, May 25, 2009

Lady's Slippers at Mansfield Hollow

Memorial Day is usually flowering time for Cypripedium acaule (Pink Lady's Slipper), a native orchid that occurs here and there in northeastern Connecticut. Last weekend, I checked out a few local populations that I knew from previous years, and didn't see much in the way of flowers or buds, so I figured it was going to be a bad year for Lady's Slippers. However, poking around Mansfield Hollow State Park today, I ran across some really impressive stands of this somewhat uncommon wildflower. There was a little evidence of damage from deer and two-legged vermin (one plant pulled up and left by a trail), but also many dozens of plants at the peak of bloom.

The Mansfield Hollow and Mansfield Center region is underlain by thick layers of rough, nutrient-poor sand and gravel left over from the glaciers. The trees are mostly White Pine and various oaks, and there are blasted heaths of bare sand where vegetation has never managed to recolonize old roads or gravel pits. There's a neat overview of the local geology here. However, areas with exceptionally poor soil like this are always home to interesting plants.

Dry, acidic woods like these are the typical home of Cypripedium acaule. The plants seem to favor somewhat open sites in the forest, and patches of Lady's Slippers tend to come and go over the years as old sites get overgrown and new gaps open up. The long, toothy leaves in the background are an American Chestnut sprout, another frequent component of the flora in this type of habitat.

In the harshest spots where the orchids hang on, they're shorter than the plants deeper in the woods. This was a population under some stunted pines near an open gravel slope; the canopy was thin enough and the soil dry and poor enough that there were also patches of Reindeer Lichen (Cladonia rangiferina).

Pink Lady's Slipper is protected in Connecticut (doubly so in state parks), so visitors should tread lightly around the plants, and not pick or dig them under any circumstances. In any event, the plants need very specialized conditions to grow and are nearly impossible to transplant (gardeners should not take that as challenge! Seriously, it is cruel and wrong to swipe these plants from the wild), and are best enjoyed in situ.

Saturday, May 16, 2009

CSSM Show at Tower Hill

The third annual Cactus and Succulent Society of Massachusetts Show is going on this weekend, at the Tower Hill Botanic Garden in Boylston, Mass. I was there early this morning for judging duties, and was impressed by the quality of the plants on display and the enthusiasm of the CSSM membership.

The sales area included about half a dozen vendors selling C&S, rock garden plants, pottery and even Amorphophallus corms.

The oranges were moved outside of the Orangerie for the summer, wrapped in fabric temporarily until they acclimate to the sun, I assume.

The territory freed up inside of the Orangerie was used for the judged cactus and succulent show. The Tower Hill greenhouse was one of the best settings I've ever seen for a plant show; natural lighting and an airy space really make a difference.

The grounds at Tower Hill are beautiful, if you need a break from cacti. The lilacs are just a little past their peak this weekend.

Friday, May 1, 2009

Lachenalia patula: a Bulb with Succulent Leaves

Lachenalia patula in late March. Material from Liebendal, near Vredendal, Western Cape, South Africa.

Bulbs with truly succulent aboveground leaves are almost unheard of: the whole point of having a bulb is that the foliage leaves can be active when growing conditions are optimal, and be dropped as soon as heat, drought or cold brings growth to a halt. In the majority of bulbous plants, even those from deserts, the only significant storage of water and nutrients occurs in the modified subterranean leaves that form the bulb itself. Lachenalia patula is almost unique*, as a bulb with chunky, low-surface-area foliage leaves full of water-storing tissue.

Lachenalia patula is a winter-growing bulb from arid areas in the Western Cape of South Africa. As far as I know, it is restricted to the southern parts of a desolate-looking but botanically rich area called the Knersvlakte, on flats and rolling hills often covered with white quartz pebbles. The bulbs of L. patula are small compared to the rest of the plant, only about 1 cm across, and covered in blackish tunics. Most of the approximately 70 species of Lachenalia come from seasonally moist habitats in the winter-rainfall zone of South Africa, and have thin leaves. Lachenalia patula’s succulent leaves may be a special adaptation to harsh conditions in the Knersvlakte.

In cultivation, L. patula needs very strong sun, and does well in cramped pots of poor, well-drained soil. In winter, the soil should be kept just slightly moist at all times: don’t let it stay soggy, but be sure that the leaves don’t start to wilt. The flowers tend to emerge in late March for me, and have a moderately strong sweet smell. They always seem to bloom about a week too early to look good for the CCSS Show. The plants rapidly go deciduous in April, as the seed ripens. As with other winter bulbs, the pot can be stored somewhere out of the way and neglected during the long warm weather dormancy.

Lachenalia patula can be propagated by seed, which are best sown in early autumn, and take two to three years to yield flowering-sized bulbs. The seedlings are agreeably peculiar little things, with perfectly cylindrical leaves, as opposed to the channeled leaves of adult plants. Like other lachenalias, L. patula can also be started from leaf cuttings, which are most likely to succeed if taken early in the growing season, as soon as the leaves are expanded.

*A few species of Drimia and Ornithogalum, including the weird O. unifoliatum, also have convincingly succulent foliage leaves.