PuAcA. LEGUMINOS^. 343 



lets, smaller flowors, &c.' The wholo plant is silvery-white and as soft as 

 cotton to the touch: the young legumes appear like pellets of cotton." Nutlall. 



3. P. sericea (Nutt. ! mss.) : " dwarf, depressed, densely and canescently 

 silky-villous ; caudex diirusely branched ; flowering branches very short, 

 thickly clothed with the imbricated scarious lacerated and very hairy stipules; 

 leaves small, on rather slender petioles; leatUts cuneate-oval or oblanceolate; 

 (flowers purple, very numerous); peduncles filiform, a little longer than ihe 

 leaves, 2-6-flowered ; segments of the calyx subulate, about the length of the 

 lube; legume (young) small, acuminate, many-seeded, villous." 



"On the high hills of the Platte near the Rocky Mountains. — A very ele- 

 gant and curious species, forming a dense tuft, spreading from a few inches 

 to a foot or more in diameter, densely clothed in every part with a silvery 

 villous pubescence. Leaves crowded : leaflets scarcely one-fourth of an 

 inch long. Stipules large, very thin, villous on the outside, and closely im- 

 bricated, so that the branches appear to be clothed with a thick woolly cover- 

 ing. Bracts subulate. Flowers small, fine purple." Nuttall. 



§ 2. Leaves vmequally pinnate, rarely 1-3-foliolate. — Phaca proper. 



♦ Legumes large, memhrmiaceous, much inflated. 

 t Flowers ocliroleucous. 



4. P. megacarpa (Nutt. ! mss.) : " almost stemless, at length nearly gla- 

 brous; leaves on long petioles; leaflets 4-5 pairs, roundish, slightly petiolu- 

 late, rather distant and often somewhat alternate ; racemes few- (3-6-) flow- 

 ered, much shorter than the leaves ; flowers very large ; calyx tubular, the 

 lanceolate-subulate teeth rather shorter than the tube ; legumes very large 

 and much inflated, ovate, acuminate, glabrous, nearly sessile. 



"Plains of the Rocky Mountains. — A rather robust species, with numer- 

 ous short subterranean stems an inch or two in length, somewhat toothed 

 with the short persistent stipules ; somewhat allied to Astragalus longiflorus, 

 but a true Phaca; the pods never pulpy, and the petioles not adnate to the 

 petiole." Nuttall. — About a span high. Leaves a little succulent, at first 

 slightly strigose: leaflets about half an inch in breadth, broadly ovate or 

 roundish oval, often emarginate. Flowers nearly an inch in length: vexil- 

 lura emarginate. Legumes 2i inches long and an inch in width when ma- 

 ture, many-seeded. 



5. P. Nattallii : "stem decumbent, low, sparingly branched, pubescent or 

 nearly glabrous ; leaves on short petioles, canescently pubescent when young; 

 leaflets approximated, 15-19 pairs, linear-oblong, somewhat narrowed at the 

 base, obtuse, often emarginate, villous-tomentosc on the midnb beneath; sti- 

 pules membranaceous, triangular, acuminate ; peduncles longer than the 

 leaves ; raceme spicate ; calyx nearly glabrcus, the teeth subulate, about half 

 the length of the tube ; legume large, inflated, at first pubescent, ventricose- 

 ly carinate, acuminated with the pointed style, sessile; flowers ochroleucous, 

 the keel tipped with a pale purple spot." — P. inllata, Nutt. ! mss., not of Gillies. 



"Borders of woods near the sea, St. Barbara, California. April. — Allied 

 to P. trichopoda, but with a somewhat difiereut habit, large flowers, and ses- 

 sile fods." Nuttall. — Apparently near P. densifolia, S'/HiV/j ; a C'alifornian 

 species which we know only from the description, and which Mr. Nuttall 

 seems not to have met with ; but that species is said to have reddish flowers, 

 &c. The raceme or spike is oblonir, rather compact, with the flowers at 

 length reflexed. The calyx when young is pubescent with blackish hairs. 



6. P. trichopoda. (Nutt. ! mss.) : " slightly pubescent ; stem stout and 

 erect, branching; leaves subsessile ; leaflets 16-2G pairs, approximated, linear- 



