10.5 nun long; ovary glabrous; ovules 24-36; pod erect, 

 sessile, continuous with receptacle, in profile narrowly 

 oblong or ovate-oblong, 12-17 x 3-6.5 mm, strait or 

 slightly incurved, obtuse at base, abruptly contracted 

 into a short, laterally compressed beak, otherwise 

 dorsoventrally compressed, carinate ventrally by the 

 cordlike suture, flattened or openly sulcate dorsally, 

 the lateral angles rounded, the green, fleshy valves 

 becoming coriaceous, stramineous, inflexed as an almost 

 complete or complete septum ±1 mm wide; dehiscence 

 through the narrowly gaping beak while pod yet attached 

 to raceme-axis. 



3. Diagnostic characters: The following combination of 

 features can be used to separate A. terminalis from other 

 Montana species of Astragalus (adapted from Dorn 1984) : 



Leaves on stem, with 11-21 leaflets, these not awl shaped 

 Hairs on leaflets attached towards their middle 



(dolabriform) 

 Stipules not united on the side of the stem opposite the 



petiole 

 Calyx tube less than 6 . 5 mm long, banner 11-16.5 mm long 



B. GEOGRAPHIC DISTRIBUTION 



1. Species range: "the sources of the Missouri, Snake, and 

 Salmon Rivers in central Idaho, southwest Montana, and 

 immediately adjacent Wyoming (Barneby 1989)." 



2. Montana distribution: scattered populations across southern 

 Beaverhead and Madison counties. 



3. Occurrences in the study area: One population was found on 

 BLM land in Limekiln Canyon in the northeast part of the 

 Tendoys. 



C. HABITAT 



For the Intermountain region, Barneby (1989) describes the 

 habitat as "open stony hillsides and benches along rivers, 

 commonly associated with low sagebrush and calcareous 

 bedrock." In this study area, the Limekiln Canyon population 

 occurs in undisturbed Festuca idahoensis / Agropyron spicatum 

 grasslands on dry, northeast facing slopes above an ephemeral 

 stream. Other associated plants include Castilleja 

 pallescens, Cbrysothamnus nauseosus, Lesquerella alpina, and 

 Phlox hoodii. Soils are silty and derived from limestone. 



D. POPULATION BIOLOGY 



The population at the Limekiln Canyon site was estimated to 

 consist of 500 to 1,000 plants covering 2 to 5 acres. On June 

 8, the population was at an early flowering stage. The 

 viability and health of this population were rated excellent. 



16 



