|
Cryptantha crassipes, a herbaceous perennial in the Borage family, is an unusual clump-forming plant with blue-grey, spathulate, sessile leaves to 4 cm long. Clumps develop gradually, beginning, of course, as seedlings, then forming a new ring of leaf-clusters each growing season. A black sooty fungus-like growth is found on bases of the majority of the clumps, and occasional clumps are entirely black, appearing dead. Flowers are borne on short racemes, to 15 cm tall, raised well above the foliage. The corolla is a fused, salverform type, with a short, white 0.5 cm tube flaring abruptly out to the petals, ca. 5-10 mm across. At the junction of the flared portion is a bright yellow ring. During the 1930's, a claim was made that flowers are heterostylic, with 2 different style lengths, causing the plants to be obligate outcrossers. Higgins discounted this, and Hughes has confirmed it in a 1992 study. This could be a possible limiting factor to reproductivity, especially if pollinators are scarce. The fruits/ seeds are 3-4 nutlets;usually four, when conditions are correct for complete fruit development. Plants flower and fruit in April/May.
Plants are limited to an area of slightly over 100 square miles in Brewster County in west Texas. The species is endemic to a geologic formation of creamy yellow limestone with exceptionally high gypsum levels. The limestone forms very thin plates between which can be found many fossils. The majority of the formation is almost completely plant-free and has a strange unearthly appearance, with a highly reflective surface. Around the periphery of this unique formation can be found relatively high densities of Cryptantha, with a few individuals straying onto the formation proper. Associated species, limited to the adjoining darker soil type derived from volcanic rock, include Berberis trifoliata, Dasyliron wheeleri, Amsonia longiflora, Krameria sp., Dyssodia sp., Leucophyllum candidum, Larrea tridentata, Bouteloua sp., Condalia warnockii and Eriogonum.
Threats to the species include limited habitat, low population numbers, development and off-road vehicle uses. Ten years ago, the land was divided and made available for sale to developers. In the last two years, new roads and utility boxes have appeared. In such a desolate, xeric place, the sight of human habitation would indeed be startlingly anomalous. A mine has been expanded and subsequently closed as prices of the mined material dropped. The potential for complete extirpation of this species is alarmingly real, compared to ten years ago when the potential for urban development seemed very remote. As this 100 square mile area is the only place on earth where Cryptantha crassipes can grow, consideration should be given to a Nature Conservancy-type approach, with an individual or organization purchasing the area and managing it as a conservation easement. The land has a spare, extra-plantetary beauty, and a combination of colors that make it a remarkable sight.
In 1990 the Desert Botanical Garden began a conservation seedbank of this species, and has collected seeds almost annually since. The USFWS lists the species as endangered, and allows the Garden to collect seeds from only 50 plants per year, from each population. Generally the Garden has collected from only 2-3 sites annually. Seeds have been produced in cultivation from plants grown from field-collected seeds. The primary focus of Garden efforts has been to continue to build a seedbank of field-collected seeds, and to store it in 2 places. Collections are divided, one portion kept at DBG and a portion stored at National Seed Storage Lab in Ft. Collins, Colorado.
|
|
