LEGUMINOSAE (PULSE FAMILY) 513 



26. DALEA Juss. 



Calyx 6-cleft or -toothed. Corolla imperfectly papilionaceous ; petals all on 

 claws ; the standard heart-shaped, inserted in the bottom of the calyx ; the 

 keel and wings borne on the middle of the monadelphous sheath of filaments, 

 which is cleft down one side. Stamens 10, rarely 9. Pod membranaceous, 

 1-seeded, indehiscent, inclosed in the persistent calyx. Mostly herbs, more 

 or less glandular-dotted, with minute stipules ; the small flowers in terminal 

 spikes or heads. (Named for Samuel Dale, 1659-1739, an English botanist.) 

 PAROSELA Cav. 



1. D. alopecuroides Willd. Erect annual, 3-6 dm. high ; leaflets 19-35, gla- 

 brous, linear-oblong ; flowers light rose-color or whitish, in cylindrical spikes ; 

 bracts ovate-lanceolate, acuminate, deciduous ; calyx very villous, with long 

 slender teeth. (Parosela Dalen Britton.) Alluvial soil, 111. to Minn, and 

 Ala., w. to the Rocky Mts. Aug., Sept. (Mex.) 



2. D. enneandra Nutt. Erect perennial, 3-12 dm. high, branching; leaflet* 

 5-13, linear, 4-6 mm. long ; spikes loosely flowered ; bracts conspicuous, per- 

 sistent, almost orbicular and very obtuse ; petals white ; calyx densely villous, 

 the long teeth beautifully plumose. (Z>. laxiflora Pursh.) Dry soil, la. and 

 Mo. to Tex. and Col. May-Aug. 



27. PETALOSTEMUM Michx. PRAIRIE CLOVER 



Calyx 5-toothed. Corolla indistinctly papilionaceous ; petals all on thread- 

 shaped claws, 4 of them nearly alike and spreading, borne on the top of the 

 monadelphous and cleft sheath of filaments, alternate with the 6 anthers ; the 

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

 Pod membranaceous, inclosed 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 peduncled heads 

 or spikes. (Name, often but not originally spelled Petal ostemon, combined of 

 the two Greek words for petal and stamen, alluding to the peculiar union of 

 these organs in this genus.) KUHNISTERA Lam. 



* Corolla rose-colored. 



1. P. purpureum (Vent.) Rydb. Smoothish; leaflets 6, narrowly linear; 

 heads globose-ovoid or short-cylindrical when old ; bracts pointed, not longer 

 than the silky-hoary calyx. (P. violaceum Michx. ; Kuhnistera MacM.) Dry 

 prairies, Ind. to Man. and La., w. to the Rocky Mts. June-Aug. 



2. P. villbsum Nutt. Soft-dotony or silky all over; leaflets 13-17, linear or 

 oblong, small (8-10 mm. long) ; spikes cylindrical, 2.6-12 cm. long, short- 

 peduncled, soft-villous. (Kuhniastera Ktze.) Sandy soil, Wise, to Sask. and 

 Tex., w. to Rocky Mts. July. 



3. P. folibsum Gray. Smooth, very leafy; leaflets 15-29, linear-oblong; 

 spikes cylindrical, short-peduncled ; bracts slender-awned from a lanceolate 

 base, exceeding the glabrous calyx. (Kuhniastera Ktze.) River-banks and 

 rocky hills, 111. and Tenn. July-Sept. 



* * Corolla white. 



4. P. multifl6rum Nutt. Glabrous throughout, erect, branching ; leaflets 

 3-9. linear to oblong ; heads globose, the subulate-setaceous bracts much 

 shorter than the acutely toothed calyx. (Kuhnistera Heller.) Prairies, w. 

 la. (Pommel} to Ark. and Tex. Aug. 



5. P. cdndidum Michx. Smooth; leaflets 7-9, lanceolate or linear-oblong; 

 heads short-cylindrical; bracts awued, longer than the nearly glabrous calyx. 

 (Kuhniastera Ktze.) Dry prairies, Ind. to Man., La., and w. to the Rocky 

 Mts. June, July. 



GRAY'S MANUAL 33 



