54 
Artificial Key to Species. 
I. Plants with globose tubers. 
* Floxvets yellow : oil-tubes solitary. 
Fruit puberulent Conn, fi 
Fruit glabrous. 
Irivolucels wanting ambiguum, 1 
Involucels conspicuous cireumdutum, 8 
* * Flowers white. 
Oil-tubes numerous. 
Fruit rough-puberulent Watsoni, 3 
Fruit glabrous farinosum, 5 
Oil-tubes solitary. 
Fruit wings as broad as body or broader eurycarpum, 12 
Fruit wings half as broad as body. . . Canbyi, 2 
Fruit wings narrower, thickish and involute Hendersoni, 1 
Root moniliform Oeyeri, 4 
II. Plants without globose tubers. 
* Flowers 'purplish Austhm, 25 
* * Flowers white. 
Oil -tubes numerous. 
Fruit tomentose tomentoHum, 14 
Fruit with abundant close pubescence, and prominent 
dorsal ribs Mohavense, 15 
Fruit sparsely pubescent, and with rather obscure dor- 
sal ribs Navadense, 1(! . 
Fruit glabrous. 
Plant glabrous CusicM-i, 32 
Plant closely pubescent ^ Parishii, 31 
Oil-tubes solitary. 
Fruit pubescent dusycarpum, 13 
Fruit glabrous. 
Fruit large (5 to 12 lines long); pubescent plants. 
Fruit wings as broad as body or broader eurycarpum, 12 
Fruit wings narrow macrocarpum, 11 
Fruit small (2 to 5 lines long). 
Fruit round: plant pubescent nudicaule, 17 
Fruit oblong: plant glabrous Ctisickn, 32 
Oil-tubes obsolete bicolor, 30 
* * * Flozvers yellow. 
Oil-tubes obsolete. hicolor, 30 
Oil-tubes solitary. 
