ROBINSON AND GREENMAN. — MEXICAN PLANTS. 385 



bluffs of a barranca near Guadalajara, 26 September, 1891 (no. 

 5179), and again on hillsides near the same locality, 6 September, 

 1893 (no. 4522). 



Var. exiguum. Very similar to the preceding, but the leaflets of 

 the 1-3-foliate upper leaves almost linear : segments of the pod a little 

 broader. — D. exiguum, Gray, PI. Wright, ii. 4G ; Torr. Bot. Mex. 

 Bound. 57. — New Mexico, Wright (no. 1010) ; Santa Cruz, Sonora, 

 Thurber (no. 933), and San Jose del Cabo, Lower California, Brande- 

 gee (no. 145). Although referred to D. Neo-Mexicanum, Gray, by 

 Dr. Watson, Bibl. Index, 217, this variety appears to us distinct from 

 that species which has an essentially flat pod and leaflets usually 

 narrow throughout. 



Var. annuum. Leaves unifoliate (rarely one or two trifoliate) : 

 leaflets broadly ovate, rather large, \\ inches long : segments of the pod 

 1^-1 1 lines broad. — D. annuum, Gray, PI. Wright, ii. 46. Referred 

 to D. spirale by Watson, Bibl. Index, 218. — New Mexico, Wright, 

 (no. 1009 a); Sonora, Thurber (no. 934). 



Var. Bigelovii. Leaves chiefly trifoliate, with oblong-lanceolate 

 leaflets (about 1-1^ inches long), one or two of the lowest leaves 

 unifoliate with a small broad leaflet: segments of the pod 1^ lines or 

 more in breadth, slightly twisted. — D. Bigelovii, Gray, PI. Wright. 

 ii. 47. D. Neo-Mexicanum, var. Bigelovii, Wats. Bibl. Index, 217 ; 

 referred to D. spirale by Grisebach, Fl. Brit. W. I. 188. — New 

 Mexico, Wright (no. 1012) ; Sonora, Thurber (no. 9o5) ;. W. Texas, 

 Havard (no. 22) ; San Luis Potosi, Parry S; Palmer (no. 181), 

 Schaffner (no. 796 in part) ; S. Arizona, Rothrock (no. 663) 

 Lemmon (no. 539) ; Mexican Bound. Surv. (no. 277); Chihuahua, 

 Pringle (no. 612). This variety differs from D. Neo-Mexicanum in 

 its broader leaflets and in the somewhat twisted segments of its 

 legumes ; from variety transversum it differs, in its decidedly broader 

 pods, as well as in its generally taller habit and larger leaflets. 



Phaseolus monospermus. Stem slender, twining, light-colored, 

 sparingly pubescent with hooked hairs: stipules ovate, scarcely a line 

 long; petioles slender, 1-1|- inches long; leaflets 3, deltoid-ovate, 

 entire, membranaceous, green on both surfaces, narrowed to an obtuse 

 and mucronate apex, subtruncate at the base, finely ciliated upon the 

 margins and veins, 15-22 lines long, three fourths as broad; stipels 

 minute, spreading : racemes 4—6 inches long ; rachis pubescent, florif. 

 erous from below the middle ; bracts ovate, obtuse, a line in length ; 

 pedicels twice as l^ng, single or in pairs : flowers small, purplish : 

 calyx about a line long, 5-:oothed : vexillum 2 lines long, equally 

 vol. xxix. (n. s. xxi.) 25 



