The Chalk Buttes population consists of six vigorous single- 

 stemmed plants, scattered along 1.6 km (1 mi) of ridge top. 

 It is possible that both the Chalk Buttes and Long Pines 

 populations are waifs, with core populations elsewhere, since 

 they are occur on restricted microhabitat. 



2. Reproduction: It is not known if seed production occurred 

 since no plants were found in late August, and no fruits were 

 observed at any time. It is possible that the plants 

 underwent normal dessication during the July-August drought in 

 the area, and that nothing remained to be seen. 



The genus in general is adapted for cross-pollination in 

 having stigmatic glands that adhere to insect visitors along 

 with pollen masses (pollinia) for conveyance to other plants 

 (Hitchcock and Cronguist et al. 1984). 



3. Competition: Both populations occur on a relatively 

 sparse vegetation, though not on unvegetated habitat. This 

 suggests that the species is an early-succession species but 

 not a pioneer, and can not compete with denser and taller 

 grass cover. 



4. Herb ivory: The decumbent habit of the plant, growing flat 

 on the ground, makes it almost unavailable for cattle grazing. 

 Species of this genus are unpalatable due to the milky latex. 

 Concentrated trampling by cattle could be deleterious at the 

 Long Pines site, but this not likely due to the open nature of 

 the site, the sparse vegetation, and lack of livestock 

 improvements such as stock tanks, where cattle tend to 

 congregate. 



F. Assessment and management recommendations: The Asclepias 

 stenophylla did not produce viable fruits in 1994, populations are 

 small, and the rest of District information is preliminary for 

 evaluating status, so we recommend it for further consideration by 

 Custer National Forest as a watch species. 



No threats are present at the Chalk Buttes site. None of the 

 threats are imminent at the Long Pines site, though it is a short 

 distance from a Forest Service road, and could be affected by road 

 construction, or "borrowing" of the sandy soil. Expansion of the 

 blowout could also impact the population, though the current level 

 of livestock use does not appear to be harmful, and may be 

 beneficial in keeping back invasion of more vigorous grasses. The 

 blowout appears to have formed along an old cattle trail, and would 

 be analagous to blowouts formed along game trails. It contains two 

 other rare species ( Dichanthelium wilcoxianum , Penstemon 

 angustifolius ) , and in its present condition appears as a natural 

 part of the landscape. 



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