350 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Specimens examined: ChehalisCoun„y, La;/(& 1197; Walla Walla, LecJcenhy, •Juno, \S98: 

 Blue Mountains, Piper, July, 189G; Palouse City, Moore, June, 1893; Henderson, July, 1892. 

 Zonal distribution: Arid Transition. 

 The tj'pe is Piper 1489, collected on Cedar Mountain, Latah County, Idaho. 



PETALOSTEMTJM. 



1. Petalostemum omatum Dougl.; Hook. Fl. Bor. Am. 1: 138. 1830. 



Type locality: " Frequent in the arid prairies near the Blue Mountains of Lewis [Snake] 

 River, North-West America." Collected by Douglas. 



Range: Eastern Washington, eastern Oregon, and south Idaho. 



Specimens examined: Pasco, Piper 2973; LecJcenby in June, ^898; Walla Walla, Lyall 

 in 1860; near Columbia and Snake rivers, Brandegee 714. 



Zonal distribution: Upper Sonoran. 



LXJPINTJS. Lupine. 



Subgen. I. PLATYCARPOS S. Wats.— Ovary 2-ovuled, forming a 

 short and relatively broad 2-(l-)seeded pod; iinnuals or biennials 

 with deep often lignescent taproot and persisting cotyledons. 



Peduncles 1 to 2 cm. long; flowers small; corolla about 1 cm. long 1. i. pusiJJns. 



Peduncles 5 to 15 cm. long; flowers larger; corolla 1.5 cm. long 2. L. ndcrocarpus. 



Subgen. II. LUPINUS proper. — Ovary 3 to raany-ovuled, forming an 



oblong to linear several-seeded pod; cotyledons not persisting. a 

 § 1. MiCRANTHi. — Annuals, slender, branching from the base; leaflets 



glabrous on the upper surface. 

 Flowers subsessile; wings oblong, 6 mm. in length; corolla usually 



pale purple 3. L. micranthus. 



Pedicels 4 mm. long; corolla deep blue; wings 8 mm. long 4. L. hicolor. 



§2. Sericei. — Perennials; calyx subsyraraetrical at the base; corolla 

 blue, varying to white or roseate; keel usually ciliate; leaflets 

 appressed-pubescent and silky (rarely tomentose) on both sur- 

 faces, canescent. 

 Stems scapose or subscapose, 7 to 25 (rarely 40) cm. high; leaves 

 chieflj' basal; flowers sessile or on very short pedicels. 

 Very dwarf (7 to 15, rarely 20, cm. high), cespitose; flowers subses- 

 sile, small; keel 6 to 8 mm. long. 



Leaflets 5 to 8, veiy small, 6 to 10 mm. long 5. L. hjallii. 



Leaflets 7 to 12, at least 12 to 20 mm. long. 



Densely and somewhat shaggy sericeous-pubescent; vexilkun 



obovate-oblong 6. L. aridits. 



Covered with a fine and closely appressed sericeous pubescence; 



vexillum suborbicular 7. L. minimus. 



oThe following key ^\^ll aid in locating a species in its proper section: 



Annuals, branching from the base; flowers small 1. Micranthi. 



Perennials. 



Calyx saccate or spurred at the base 6. Calcarati. 



Calyx symmetrical or nearly so at base. 



Flowers yellow . 5. Sulphurei. 



Flowers purple or violet. 



Leaves green, the pubescence thin, never silky or villous 4. Rivulares. 



Leaves sericeous or villous. 



Pubescence sericeous _ 5. Sericei. 



Pubescence villous 6. Saxosi. 



