PEA FAMILY 559 



narrowly linear, 1-2 cm. long, sparsely strigose and glandular-dotted; racemes 5-10 cm. long, 

 loosely flowered ; pedicels 2-3 mm. long ; calyx 4-5 mm. long, sparsely strigose toward the apex 

 and on the teeth, rather inconspicuously glandular-dotted, the teeth triangular, scarcely 1 mm. 

 long; corolla 8-10 mm. long; pod 7 mm. long, conspicuously glandular-dotted over the entire 

 surface. 



Desert washes, Lower Sonoran Zone; Colorado Desert, California, to southwestern Arizona and northern 

 Lower California. Type locality : "Diluvial banks of the Colorado." Feb.-May. 



Dalea Schottii var. puberula (Parish) Munz, Man. S. Calif. 263, 598. 1935. Young branches, young 

 leaves and calyces canescent-puberulent. Western edge of the Colorado Desert, south of the Santa Rosa Moun- 

 tains, California. 



10. Dalea spinosa A. Gray. Desert Smoke Tree. Fig. 2769. 



Dalea spinosa A. Gray, Mem. Amer. Acad. II. 5: 315. 1855. 

 Asagraea spinosa Baillon, Adansonia 9: 233. 1870. 

 Parosela spinosa Heller, Cat. N. Amer. PI. ed. 2. 7. 1900. 



Shrub or small tree 2-6 m. high, the branchlets spinescent and densely silky-canescent, 

 glandular-dotted. Leaves simple, very sparse and often wanting, linear or linear-lanceolate., 5-12 

 mm. long, glandular-dotted and silky; racemes numerous, 2-3 cm. long, the rachis spinescent 

 even at flowering time; flowers usually about 8-12, short-pedicelled ; calyx 4 mm. long, silky, 

 the tube 10-ribbed and beset with a more or less distinct band of conspicuous rounded amber- 

 colored glands, the teeth ovate, scarcely as long as the tube ; corolla bright blue-purple, 8-10 mm. 

 long; ovules 4-6; pods about 6 mm. long, pubescent about the base of the style, beset with con- 

 spicuous amber-colored glands. 



Desert washes, Lower Sonoran Zone; Colorado Desert, California, to southwestern Arizona, Sonora, and 

 Lower California. Type locality: "Arroyas of the Gila; and on the desert west of the Colorado." June-July. 



14. PETALOSTEMON Michx. Fl. Bor. Amer. 2:48. 1803. 



Perennial or rarely annual herbs, more or less glandular-dotted. Leaves odd-pinnate 

 with entire leaflets. Flowers in terminal spikes, perfect ; bracts deciduous ; calyx cam- 

 panulate, 10-nerved; lobes triangular to lanceolate. Corolla indistinctly papilionaceous, 

 purple, pink, white, or yellowish ; standard free, the others inserted at the mouth of the 

 staminal tube and alternating with the free portion of the filaments. Stamens 5, monadel- 

 phous below. Style filiform; ovary 2-ovuled. Pod membranous, obliquely obovoid to 

 subglobose. [Name Greek, referring to the united petals and stamens.] 



A genus of about 50 species, native of North America and Mexico. Type species, Petalostemon candidum 

 Michx. 



Standard rounded at apex; spikes oblong, 15 mm. broad in fruit; bracts much exceeding the calyces. 



1. P. ornatus. 



Standard emarginate at apex; spikes cylindric, 9-10 mm. broad in fruit; bracts about equaling the calyces. 



2. P. Searlsiae. 



1. Petalostemon ornatus Dougl. Blue Mountains Prairie Clover. Fig. 2770. 



Petalostemon ornatus Dougl. ex Hook. Fl. Bor. Amer. 1: 138. 1830. 

 Dalea ornata Eaton & Wright, N. Amer. Bot. 219. 1840. 

 Kuhnistera ornata Kuntze, Rev. Gen. PI. 192. 1891. 



Perennial with a branched woody crown; stems of the season 3-6 dm. high, glabrous, punc- 

 tate. Leaves ascending, 3-5 cm. long ; leaflets usually 5, obovate to broadly elliptic, 1-2 cm. long, 

 rounded or obtuse at the apex, glabrous, glandular-punctate beneath ; spikes oblong, 12-15 mm. 

 broad, 2-4 cm. long ; bracts broadly obovate, abruptly acuminate, densely villous ; calyx 5 mm. 

 long, densely villous ; lobes lanceolate, nearly as long as the tube ; corolla rose-colored ; standard 

 oval, rounded or truncate at the apex ; pod 4 mm. long, obliquely obovoid, pubescent. 



Dry usually sandy soils, Upper Sonoran Zone; southeastern Washington to Lake County, Oregon, 

 east to Idaho. Type locality: prairies near the Blue Mountains of Lewis [Snake] River, Washington or 

 Oregon. June-Aug. 



2. Petalostemon Searlsiae A. Gray. Searls' Prairie Clover. Fig. 2771. 



Petalostemon Searlsiae A. Gray, Proc. Amer. Acad. 8: 380. 1873. 

 Kuhnistera Searlsiae Kuntze, Rev. Gen. PI. 192. 1891. 



Perennial with a branched woody caudex, stems of the season 3-5 dm. high, decumbent at 

 base, glabrous, glandular-punctate. Leaves 3-5 cm. long; leaflets 3-7, oblong to oblanceolate, 

 10-15 mm. long, involute on the margins, pale green, conspicuously punctate beneath.^ acute at 

 each end ; spikes long-peduncled, cylindric, about 1 cm. thick and 1-4 cm. long in fruit ; bracts 

 rhombic-oblanceolate, acute or short-acuminate, pubescent below, glabrous above ; calyx 4 mm. 

 long, villous ; lobes lanceolate, acute or acuminate, scarcely as long as the tube ; corolla rose- 

 colored ; blade of the standard cordate, 3 mm. long, the claw 4 mm. long. 



Dry gravelly or sandy soils, Sonoran Zones; Providence Mountains, and Pahrump Valley, Mojave 

 Desert, California, to southern Nevada, Utah, and northern Arizona. Type locality: Pahranagat Moun- 

 tains, southern Nevada. May— June. 



15. ROBINIA L. Sp. PI. 722. 1753. 



Trees or shrubs with odd-pinnate leaves and showy flowers in axillary or terminal 

 racemes. Stipules small, often spiny. Calyx-teeth short and broad, the two upper slightly 



