226 XLVII. LEGUMINOS^. Trifolium. 



from the stem, petiolules scarcely 2" long, Spicate racemes terminal, solitary 

 or fascicled, 3 — 4' long. Vexillum purple, emarginate. Jn. 



2. A. CANESCENS. Niitt. Lcad Plant. 



SufTruticose and canescently villose ; Ifts. small, numerous, and crowded, 

 ovate-elliplical, subsessile, mucronate ; spikes aggregate ; Jls. subsessile ; ccd. 

 teeth equal, ovate, acute ; vex. bright blue ; leg. l-seeded. — A beautiful species, 

 3 — 4f high, in dry, sandy soils ! Wis. to La. and Rocky Mts., and is supposed 

 to prefer'localities of lead ore. Leaves 2 — 3' long. Leaflets coriaceous, 16 — 24 

 pairs, obtuse at base, 4—6" by 1—2". Spikes 2—3' long. Jl. Aug. 



16. DALE A. 



In honor of Thomas Dale, ar. English botanist of the last century. 



Calyx subequally cleft or toothed ; petals unguiculate, claws of the 

 wings and keel adnate to the staminate tube half way up ; vexillum 

 free, the limb cordate ; stamens 10, united into a cleft tube ; ovary 2- 

 ovuled ; legume enclosed in the calyx, indehiscent, l-seeded. — Mostly 

 herbaceous and glandular-pundate. Lvs. odd-pumate. Siipels 0, stipules 

 minute, setaceous. Spikes mostly dense. 



D. ALOPECURoiDEs. Willd. (D. Linnsei. Mlchx. Petalostemon. Ph.) 

 Glabrous and much branched ; Ifts. 8 — 14 pairs, linear-oval, obtuse or 

 retuse, mucronate, punctate beneath ; spikes pedunculate, oblong-cylindric, ter- 

 minal, silky; bracts about equaling the acuminate segments of the calyx.—® 

 Prairies and bottoms. 111. ! Mo., Car. Plant about 2f high, bushy and leafy and 

 pale green. Leaflets not more than 4" by 1", sessile, and nearly in mutual 

 contact. Spikes 1—2' long. Vexillum white, wings and keel pale violet. 



17. PETALOSTEMON. Michx. 



Alluding to the union of the petals and stamens. 



Calyx 5-toothed, nearly equal ; petals 5, on filiform claws, 4 of 

 them nearly equal, alternate with the stamens and united with the 

 staminate tube : stamens 5, monadelphous ; tube cleft ; legume 1- 

 seeded, indehiscent, included in the calyx. — %- Lvs. unequally pinnate.^ 

 ex-stipellate. Fls. in dense, pedunculate, temmial spikes or heads. 



1. P. CANDIDUM. Michx. (Dalca. Willd.) 



Glabrous, erect; Ifts. 7—9, all sessile, linear-lanceolate, mucronate, 

 glandular beneath; sjrikcs on long peduncles; bracts setaceous; vex. broadly 

 cordate, the other petals ovate. — A fine-looking plant, in dry prairies Southern 

 and Western States ! Stem 2— 4f high, sparingly branched, slender. Leaflets 



9 18" by 3 — 5", terminal one largest. Flowers small, white, crowded in dense 



spikes which are 1 — 3' long. Jl. 



2. P. vioLACEUM. Michx. (Dalea. Willd.) 



Minutely pubescent, erect; Ifts. 5, linear, glandular beneath; spikes 

 pedunculate, oblong or subglobose ; rex. cordate, the other petals oblong, obtuse 

 at base. — A beautiful plant, of similar habits with the last. Stem slender, stri- 

 ate, subsimple, li— 2f high. Leaflets about 1' by 1", all sessile. Spikes 1—8, 

 very dense, i— H' long. Petals of a bright violet purple. Jl. Aug. 

 18. TRIFOLIUM. Tourn. 



Gr. rpKpvWoi', (three-leaved); Lat. trifolium; Fr. irefle; Eng. trefoil. 



Calyx tubular or campanulate, 5-toothed, persistent ; petals more 

 or less united at the base, withering ; vexillum reflexed ; alae oblong, 

 shorter than the vexillum; carina shorter than the ala3 ; stamens 10, 

 diadelphous (9 & 1) ; legume short, membranous, mostly indehiscent, 

 covered by and scarcely longer than the calyx, 2 — 4-seeded ; seeds 

 roundish. — Herbs. Lvs. palmately trifoliate ; Ifts. with straight, scarcely 

 reticulated veins. Fiercer s in dense heads or spikes. 



