Part 2, 1920] FABACEAE: PSORALEAE 121 



banner white, the blade oval, 1.5-2 mm. long, the claw 2.5 mm. long; other petals blue or 

 rarely rose-purple, the blades broadly oval, oblique at the base, 2 mm. long, the claws less 

 than 0.5 mm. long; pod short-pubescent at the apex, otherwise glabrous. 



Type locality: "America" [according to several references: Veracruz]. 



Distribution: Mexico, from Verzcruz and Tepic, south; also Philippine Islands (native?). 



Illustration: L. Hort. CHIT. pi. 22. 



13. Thornbera robusta Rydberg. 



Dalea virgata M. Micheli, Bull. Herb. Boiss. 2: 442. 1894. Not D. virgata Lag. 1816. 



A stout annual; stem branched, erect, glabrous, glandular-dotted; leaves 2-3 cm. long, 

 ascending; stipules subulate-setaceous, 2-3 mm. long; rachis glabrous, margined, glandular- 

 dotted; leaflets 9-1 1, linear, 4-10 mm. long, glabrous on both sides, copiously glandular-dotted 

 beneath; peduncles terminating the branches, 1-3 cm. long; spikes dense, 2-5 cm. long, fully 

 1 cm. thick; bracts ovate, caudate-acuminate, dark, densely glandular-dotted, puberulent on 

 the back, ciliate on the margins, 6-7 mm. long; calyx-tube campanulate, 10-ribbed, silky, not 

 conspicuously glandular-dotted between the ribs; lobes subulate, 3 mm. long, plumose; banner 

 white, the blade oval, 2 mm. long, the claw 3.5 mm. long; other petals blue or purple, the blades 

 oval, nearly 2.5 mm. long, oblique at the base, the claws less than 0.5 mm. long; pod densely 

 pubescent at the apex, glabrous below. 



Type locality: Near San Jose and Buenos Ayres, Costa Rica. 

 Distribution: Guatemala to Panama. 

 Illustration: Bull. Herb. Boiss. 2: pi. 9. 



18. PETALOSTEMON* Michx. Fl. Bor. Am. 2:48. 1S03. 



Perennial or rarely annual herbs, often branched at the base, more or less glandular-dotted. 

 Leaves odd-pinnate with entire sessile or short-petioluled leaflets. Flowers in terminal, usually 

 dense spikes; bracts usually sooner or later deciduous. Calyx campanulate or turbinate, 10- 

 nerved, with triangular to lanceolate lobes, rarely much exceeding the tube, usually shorter. 

 Corolla indistinctly papilionaceous, white, pink, purple, or yellowish ; banner free, long-clawed, 

 the blade broader than those of the other petals, usually cordate or truncate at the base; 

 other petals oblong to oval, short-clawed, usually acute at the base, inserted at the mouth of 

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

 delphous below, but the filaments one fifth to one third free. Ovary sessile, 2-ovuled; style 

 filiform; stigma minute. Pod membranous, enclosed in the calyx, 1- or 2-seeded, usually 

 somewhat compressed, obliquely obovate, semi-orbicular, or somewhat lunate. 



Type species, Petalostemon candidus Michx. 



Calyx glabrous throughout or villous-ciliate on the margins of the lobes only 

 (in P. microphyUus sparingly pilose all over). 

 Stem-leaves with 3-11 leaflets. 



Banner oblong to orbicular; calyx not strongly 10-ribbed. I. Carnei. 



Banner cordate or reniform: calyx strongly 10-ribbed. 



Calyx nearly regular; petals white- II. Candidi. 



Calyx decidedly oblique, with all the lobes towards the lower side; 



petals rose -colored. IN. ProstraTI. 



Stem-leaves with 11-37 leaflets. 



Calyx nearly regular; petals rose-purple. IV. Foliosi. 



Calyx very oblique, all the lobes on the lower half of the calyx-rim; 



petals white. V. PhlEOIdeS. 



Calyx densely pubescent at least on the angles and lobes. 

 Corolla white or yellowish. 



Spikes slender, less than 1 cm. thick; leaflets 11-37. VI. Pilulosi. 



Spikes stout, dense, 1-2 cm. thick; leaflets 3-7. VII. Compacti. 



Corolla rose or purple, or bluish. 



Plants annual. VIII. Exiles. 



Plants perennial, with a woody base. 



Leaflets 9-17, more or less silky -villous, oblong or oblanceolate. IX. Villosi. 



Leaflets 3 -9, usually glabrous at least above, or pubescent in nos. 27 

 and ?>7> only. 

 Pubescence on the calyx dense and short. X. Purpurei. 



Pubescence on the calyx long, silky-pilose. XI. OrnaTi. 



* Originally published as Petaloslemum, but incorrect as ar-qtioip is masculine and has a long o in 

 the final syllable. 



