130 LKGUMIXOS.E. (I'ULSK FA.'\III.Y.) 



9. PETALOSTEMON, Mkhx. Trairie Clover. 



Calyx 5-tootIiC(l. Corulhi iiidisiiiictly papiliouaccous : petals all on thread- 

 shaped claws, 4 of them nearly similar and spreadinj;, borne on the top of the 

 monadeljjhous and cleft sheath of filaments, alternate with the 5 anthers ; tho 

 fifth (standard) inserted in the bottom of the calyx, heart-shai)ed or oblong. 

 Pod membranaceous, enclosed in the calyx, indehiscent, 1 -2-seeded. — Chiefly 

 perennial herbs, upright, glandular-dotted, with crowded odd-pinnate leaves, 

 minute stipules, and small flowers in very dense terminal and pedunded heads 

 or spikes. (Name combined of the two Greek words for petal and stamen, al- 

 luding to the peculiar union of these organs in this genus.) 



1. P. violaceus, Michx. Smoothish: leaflets 5, narrowly linear; heads 

 globose-ovate, or oblong-cylindrical when old; bracts pointed, not longer than 

 the silky-hoary calyx ; corolla rose-purple. — Dry prairies, Michigan to Minnesota 

 and southward. July. 



2. P. candidus, Michx. Smooth; leaflets 7-9, lanceolate or linear-ob- 

 long; heads oblong, when old cylindrical ; bracts awned, longer than the nearly 

 glabrous caly.x ; corolla white. — With Xo. 1. July. 



3. P. vill6sus, Nutt. SoJ'i-downij or silky a.\\ over; leaflets 1.3- 17, linear 

 or oblong, small (4" - 5" long) ; spikes cijlindricnl ( 1 ' - .5' long), short-pedunclcd, 

 soft-villous ; corolla rosi:-color. — N. Wisconsin (Lake Pepin, &c. T.J.Uale) and 

 westward. 



10. AMORPHA, L. False Indigo. 



Calyx inversely conical, 5 toothed, persistent. Standard (the other petals en- 

 tirely wanting !) wrapped around the stamens and style. Stamens 10, monadel- 

 phons at the very base, otherwise distinct. Pod oblong, longer than the calyx, 

 1-2-sceded, roughened, tardily dehiscent. — Shrubs, with odd-pinnate leaves; 

 the leaflets marked with minute dots, usually stipellate. Flowers violet or pur- 

 ple ; crowded in clustered tcrmitud spikes. (Name, apoprpr]. invitimi form, from 

 the absence of four of the petals.) 



1. A. fruticdsa, L. (False Indigo.) Eatlur pubescent or smoothish; 

 leaflets 8-12 pairs, oval, scattered; pods 2-seeded. — River-banks S. Penn. to 

 Wisconsin and southward. June. — A tall shrub : very variable. 



2. A. can6scens, Nutt. (Lead-Plant.) Low (l°-3° high), ivhitened 

 u-iih ho'iri/ down ; leaflets 1.") - 2'S pairs, elliptical, crowded, small, smoothish al)Ove 

 with age; pods 1 -seeded. — Prairies and crevices of rocks, Michigan to Wiscon- 

 sin and southwestward. July. — Supposed to indicate lead-ore. 



11. ROBInIA, L. Loclst-tree. 



Calyx short, .5-toothed, slightly 2-lippcd. Standard large and rounded, 

 turned back, scarcely longer than the wings and keel. Stamens diadclphous. 

 Pod linear, flat, several-seeded, margined on the seed-bearing edge, at length 2- 

 valved. — Trees or shrubs, often with prickly spines for stipules. Leaves odd- 

 pinnate, the ovate or oblong leaflets stipellate. Flowers showy, in hanging 

 axillary racemes. Base of the leaf-stalks covering the buds of the next year. 

 (Named in honor of John Robin, herbalist to Henry IV. of France, and his son 

 Vespasian Robin, who first cultivated the Locust-tree in Europe.) 



