D. POPULATION BIOLOGY 



The single occurrence is a large population with estimated 

 size of between 1,000 and 5,000 plants covering about 20 

 acres. When the population was discovered in late July, most 

 of the plants were in fruit with some still flowering. There 

 was evidence of inflorescence predation. The quality and 

 viability of this occurrence were rated excellent. 



E. MANAGEMENT CONSIDERATIONS 



Astragalus scaphoides is a narrow endemic that is locally 

 common in Idaho (Lesica and Elliott 1987) but uncommon in 

 Montana. The plant was recently listed as 3C by the USFWS (FR 

 Notice of Review Vol. 58, No. 158 of 9/30/93). Only three of 

 the currently known populations in the state are large. All 

 but one population are subject to livestock grazing, and 

 populations are damaged under heavy spring grazing (Lesica and 

 Elliott 1987, Lesica 1994). Spring grazing of pastures having 

 populations of A. scaphoides should be kept to a minimum. 

 This species is recommended for retaining as sensitive by the 

 BLM and for tracking by the state. 



Astragalus terminalis Wats. 

 Railhead milkvetch 



A. DESCRIPTION 



1. General description: See the genus description (page 9). 

 These are erect plants with white, nodding flowers. 



2. Technical species description (quoted from Barneby 1989): 



Potentially but sometimes shortly or obscurely caulescent 

 perennial herbs with superficial root-crown or caudex, 

 densely strigulose throughout with dolabriform hairs, the 

 foliage usually canescent, the inflorescence fuscous- 

 strigulose; stems decumbent or ascending, (2.5)5-20 cm 

 long, with at least (1)2 developed internodes, the 

 cauline axis commonly shorter than the longer 

 inflorescences; stipules submembranous , 2-6 mm long, the 

 lowest ovate, strongly or fully amplexicaul but free, the 

 upper deltate-, triangular-, or lance-acuminate, often 

 reflexed; leaves (3)5-17 cm long; leaflets (11)13-21, 

 either oblong-ovate, emarginate to retuse, or narrowly 

 oblong-elliptic, obtuse to subacute, 3-17 mm long; 

 peduncles incurved-ascending, 6-20(24) cm long; racemes 

 7-25 flowered, the flowers nodding at full anthesis, the 

 early elongating axis becoming (1.5)3-12(16) cm long; 

 calyx 4-7 mm long, the campanulate teeth 0.6-1.5 mm long; 

 petals white or suffused with palest lilac, the keel-tip 

 deeply maculate, the abruptly recurved banner (11)12-16.5 

 mm, the wings ±1-4 mm shorter, the obtuse keel (8)8.5- 



