60 LEGUMINOS^E. (PULSE FAMILY.) 



13. ASTRAGALUS, Tourn. RATTLE-WEED. 



Corolla and its slender-clawed petals usually narrow. Herbs, or a few 

 woody at base : with rather small flowers, chiefly in simple axillary spikes or 

 racemes : the peduncle commonly elongated. Gray, Proc. Am. Acad. vi. 188. 

 AVatson, Bot. King's Exp. 435. 



SERIES I. Pod completely or imperfectly 2-celled by the intrusion of the dorsal 

 suture, the ventral suture being not at all or less deeply inflexed. ASTRA- 

 GALUS, L. 



Artificial Key. 



Pod succulent, becoming thick and fleshy, sessile Nos. 1, 2, 3 



Pod not 2-celled, inflated, not mottled, sessile ; plant hirsute-canescent ... 27 

 Pod completely 2-celled, bladdery-inflated, often mottled, sessile ; plant nearly glabrous 4 

 Pod coriaceous, cartilaginous, or chartaceous, not bladdery-inflated, 



1. Conspicuously stipitate, the stipe about equalling or surpassing the calyx, 



Notsulcate 20,21 



Deeply sulcate. 



Pod glabrous, pendent 14, 15, 16 



Pod black-hairy 24 



2. Short-stipitate, 



Notsulcate 22 



Sulcate, 



Incurved, mottled 25 



Straight, 



Completely 2-celled 11, 13 



Incompletely 2-celled 23, 26 



3. Sessile. 



Completely 2-celled, 



Glabrous 5, 7 



Pubescent or hoary 8, 9, 10, 12 



Villous or woolly 6 



Incompletely 2-celled. 



Stems a span or more high 18, 19 



Stems not rising so high, or none at all. 



Pod straight or nearly so 17, 28 



Pod curved 29, 30, 31, 32 



Systematic Synopsis. 



1. Pod plum-shaped, succulent, becoming thick and fleshy, indehiscent, not stip- 

 itate, completely 2-celled. Perennials, with low leafy stems : stipules distinct, 

 nearly free : racemes short, spike-like. 



* Ovary and pod glabrous. 



1. A. caryocarpus, Ker. Grayish with an oppressed pubescence: flowers 

 violet: pod globose or ovate, usually pointed. Plains from the Saskatchewan 

 to Texas. 



2. A. MexicanilS, A.DC. Taller, greener, less pubescent : flowers lighter- 

 colored or white: calyx softly white-villous or tomentose: pod ovate-globose, 

 scarcely pointed. From Colorado to Missouri and S. Texas. 



# * Ovary hoary-hirsute : pod sometimes becoming glabrate. 



3. A. Plattensis, Nutt. Loosely villous : flowers ochroleucous or pur- 

 plish above : pod ovate, acuminate, or oblong and somewhat curved. From 

 Colorado to Nebraska and Illinois, and southward to Texas and N. Alabama. 



