1917] Butters & St. John,— North American Lathyrus 157 
stipules and a dense puberulence on the calyx and pedicels, and in 
fact throughout the plant, from West Virginia and Tennessee, north 
to Ontario, and west to Saskatchewan. 
Variety a of Torrey and Gray is by inference L. venosus of Muhlen- 
berg, but it is not described by Torrey and Gray, nor is any statement 
of its range given except in the general description and the general 
range of the species, which are so framed as to include all the varieties. 
L. venosus of Muhlenberg was, however, originally described as a 
glabrous plant with ovate obtuse leaflets, and large ovate semi-sagit- 
tate stipules. A plant corresponding entirely to this description grows 
from northern New Jersey to Virginia. 
It can be seen that these varieties of Torrey and Gray are perfectly 
. distinct entities, with a series of correlated characters, and with definite 
geographical ranges. There are in the Gray Herbarium, however, 
half a dozen specimens which grow within the range of some one of 
these entities, but which have a greater or less admixture of characters. 
Such a specimen is one collected by Frank C. Gates, no. 1682.5, June 22, 
1907, in an open grassy thicket, Winnetka, Illinois. Growing within 
the range of var. y of Torrey and Gray, it has the heavy uniformly 
distributed hirtellous pubescence of that variety, the broadly ovate 
leaflets of their var. 8 and the broad ovate-lanceolate stipules of L. 
venosus of Muhlenberg sensu stricto. The existence of such specimens 
as this has convinced the authors that the entities noted above, 
though for the most part easily recognizable, and possessing definite 
geographical ranges, should be treated as varieties rather than as 
species. In the following synopsis we have indicated the characters 
of the species and of each of the varieties, and have assigned names 
to the latter. 
LATHYRUS VENOSUS Muhl. in Willd. Sp. Pl. iii. pt. 2, 1092 (1803); 
Orobus Miihlenbergii Alefeld, Bonplandia, ix. 146 (1861). Plant 
nearly glabrous: stems stout, 4-angled, ridged and striate, but not 
winged, climbing, attaining a length of about 1 m.: stipules ovate- 
lanceolate, semi-sagittate; those of the lower nodes 2-3.5 cm. long, 
4-10 mm. broad; leaflets 10-12, elliptic or ovate-elliptic, mucronate, 
dark green above, paler beneath, with the veins prominent, 1.5-6.5 
cm. long, 1-2.8 cm. wide, opposite or sub-alternate: peduncles one 
half to two thirds the length of the subtending leaves, 5-10-flowered: 
flowers 15-20 mm. long; calyx glabrous except for the ciliation on 
the sepals; the two upper sepals short and convergent, the three 
lower, linear-lanceolate; corolla purplish. 
Type COLLECTION: “in Pensylvania, Muhlenberg.” 
