144 LEAFLElS. 



Of more easterly range in Texas, evidently; the only speci- 

 mens seen being those distributed from Fort Concho by Eever- 

 chon, and some fragments from Gillespie Co., by Jermy. 



K. vbstitum: (Engler). Distinguished from Ji. tnicrophyllum 

 chiefly by more densely pubescent foliage; but there maybe 

 other differences, for it inhabits a district in New Mexico more 

 elevated and more arid than the habitat of the type ; but it 

 also occurs in eastern Texas. 



K. HUGULOSUM. Leaflets only 5, or rarely 7, as often but 3, 

 oblong, obtuse, mucronate, revolute, villous strigulose beneath, 

 scarcely more than scaberulous above, but minutely transverse- 

 rugulose. 



Species with the best of marks, but known only by a single 

 good sheet in U. S. Herb., from Texas by Dr. Palmer, in 1880 ; 

 no other data given. 



R. KBTUBTJM. Leaflets quite uniformly 9, broader than in the 

 foregoing, oval to slightly obovate, usually retuse at the broad 

 summit, always mucronulate, the lowest pair short, round-oval, 

 very inequilateral, upper face of all deep green and as if glab- 

 rous, but with short scattered hairs from distinct muriculations, 

 lower face with scattered longer hairs and showing pinnate 

 veins. 



Near Lake Santa Maria, Chihuahua, Mex., Sept., 1899, E. W. 

 Nelson, n. 6422 as in TJ. S. Herb. Also from Santa Eulalia 

 Plains, "Wilkinson, 1885. 



R. PoTOSiNUM. Branches short, rigid, approaching the spi- 

 nescent : leaves very small : leaflets 5 to 7, oval, except the low- 

 est, these orbicular but extremely inequilateral, all deep green 

 and almost shining above, 'but with some obscure pubescence on 

 both faces. 



San Luis Potosi, Parry & Palmer, n. 126 as in U. S. Herb. 



R. cinebbum:. Very small foliage dull cinereous or glauces- 

 cent ; leaflets 5 to 7, hardly pubescent on either face, beneath 

 obviously almost divaricately feather-veined, the lowest pair oval, 

 moderately inequilateral, all the others oval or oval-oblong and 

 larger, all inclined to be revolute. 



Near Durango, Mex., 1896, Dr. Palmer, n. 91 as in U. S. 

 Herb. 



