350 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
SPECIMENS EXAMINED: Chehalis County, Lamb 1197; Walla Walla, Leckenby, June, 1898; 
Blue Mountains, Piper, July, 1896; Palouse City, Voore, June, 1893; Henderson, July, 1892. 
ZONAL DIsTRIBUTION: Arid Transition. 
The type is Piper 1489, collected on Cedar Mountain, Latah County, Idaho. 
PETALOSTEMUM. 
1. Petalostemum ornatum Dougl.; Hook. Fl. Bor. Am. 1: 138. 1830. 
Tyrer Locauity: “Frequent in the arid prairies near the Blue Mountains of Lewis [Snake] 
River, North-West America.” Collected by Douglas. 
Ranar: Eastern Washington, eastern Oregon, and south Idaho. 
SPECIMENS EXAMINED: Pasco, Piper 2973; Leckenby in June, ‘898; Walla Walla, Lyadl 
in 1860; near Columbia and Snake rivers, Brandegee 714. 
ZONAL DISTRIBUTION: Upper Sonoran. 
bd 
LUPINUS. Lupine. 
Subgen. I. PLATYCARPOS S. Wats.—Ovary 2-ovuled, forming a 
short and relatively broad 2-(1-)seeded pod; annuals or biennials 
with deep often lignescent taproot and persisting cotyledons. 
Peduncles 1 to 2 em. long; flowers small; corolla about 1 em. long.... 1. ZL. pusillus, 
Peduncles 5 to 15 em. long; flowers larger; corolla 1.5 cm, long... ... 2. L. microcarpus. 
Subgen. II. LUPINUS proper.—Ovary 3 to many-ovuled, forming an 
oblong to linear several-seeded pod; cotyledons not persisting.@ 
§ 1. Micrantur.—Annuals, slender, branching from the base; leaflets 
glabrous on the upper surface. 
Flowers subsessile; wings oblong, 6 mm. in length; corolla usually 
pale purple ..........-.-2--.------ 2-222-222-2222 + 2 -- = + -- 3. L. mieranthus. 
Pedicels 4 mm. long; corolla deep blue; wings 8 mm. long ..:..-.-.-- 4. L. bicolor. 
§ 2. Sericer.—Perennials; calyx subsymmetrical 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 
chiefly basal; flowers sessile or on very short pedicels. 
Very dwarf (7 to 15, rarely 20, em. high), cespitose; flowers subses- 
sile, small; keel 6 to 8 mm. long. 
Leaflets 5 to 8, very small, 6 to 10 mm. long......-...---.----- 5. L. lyallii. 
Leaflets 7 to 12, at least 12 to 20 mm. long. 
Densely and somewhat shaggy sericeous-pubescent; vexillum 
obovate-oblong..... 2.2... 22 .--2-- 20-2 +222 2-2 eee ee eee 6. L. aridus. 
Covered with a fine and closely appressed sericeous pubescence ; 
vexillum suborbicular......-.....-..-.-----------+-------- 7. L. minimus. 
a The following key will 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............------+-------+-+---- 2-2-2222 - eee eee 5. SULPHUREL. 
Flowers purple or violet. 
Leaves green, the pubescence thin, never silky or villous .. -. - 4. RIvULAREs. 
Leaves sericeous or villous. 
Pubescence sericeous........-.------------+---+------ 5. SERICEL, 
Pubescence villous.........-...-.---------+--------- 6. SAXosI. 
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