PEA FAMILY 173 



ASTRAGALUS Linne 1753 ASTRAGALUS 

 (Greek name of a related plant) 

 PL 28, fig. 6; PL 29, fig. 13-28. 



Sepals 5, united into a 5-toothed tube, petals 5, white, pink, red, blue 

 or yellow, standard erect, wings oblong, keel blunt, stamens 10, 9 united, 

 ovary 1-2-celled, many-seeded, pod 1-2-celled, fleshy to papery or woody, 

 splitting or remaining closed ; flowers in racemes or spikes, rarely solitary ; 

 leaves alternate, odd-pinnate, digitate or rarely simple; perennial or annual. 



I. Leaves simple or of 3 leaflets 



1. Leaves simple or apparently so, rarely of 3-5 



leaflets or at first pinnate 



a. Leaves simple, or rarely of 3-5 leaflets 



(1) Flowers purple; racemes several-flow- 



ered; stems tufted or mat-like; leaves 



silky A. caespitosus 



(2) Flowers yellowish; stems 1-2 ft. high; 



leaves smooth A. asclepiadoides 



b. Leaves apparently simple, due to the falling 



of the pinnate leaflets A. junceus 



2. Leaves of 3 leaflets, silky-silvery; stems tufted 



a. Flowers purple 



(1) Flower cluster longer than the leaves; 



calyx partly enclosing the pod A. sericeus 



(2) Flower cluster shorter than the leaves; 



calyx falling away A. tridactyticus 



b. Flowers yellowish to white; calyx enclosing 



pod A. triphyllus 



II. Leaves of 4-many leaflets, pinnate 



1. Pods 1 -celled, cross wall wanting or imperfect 



a. Leaflets 4-6, spiny-pointed ; flowers 1-3, yellow- 



ish to purple A. centrophyta 



b. Leaflets not spiny-pointed, usually 6-many 



(1) Leaflets not jointed to the axis, but seem- 



ing continuous with it, rigid, linear and 

 persistent; flowers white or yellowish; 

 pods usually hanging, often horizontal 

 or ascending A. pectindtus 



(2) Leaflets distinctly jointed by a petiole to 



the axis, not persistent 



