Lathyrus 



Leguminosae 



619 



o 50 



Map 1274 

 Lathyrus palustns 

 var. linearifolius Ser. 



Map 

 LYthyrus palustns 

 var. myrtifolius (Muhl.) Gray 



50 

 275 



ton and Brown, Illus. Flora, ed. 2.) Hairy Veiny Pea. Map 1272. Infre- 

 quent to very rare in some of the counties of the lake area where it is gen- 

 erally found in dry, sandy soil in open, black oak woods, in prairie habitats, 

 and rarely in a marshy habitat. I have had this variety under cultivation 

 for a few years and it is spreading rapidly by underground stems. There 

 have been four reports for the species from the northern counties but I 

 am referring them all to the variety. 



Ont. to Sask., southw. to W. Va., Tenn., and N. Dak. 



4. Lathyrus palustris L. Marsh Pea. Map 1273. Infrequent in the lake 

 area in swamps and marshes, on the low borders of lakes, in springy places 

 along streams, and in a drier habitat in prairies. It has been reported 

 from several places south of the lake area and, without doubt, it was 

 formerly found in prairie habitats and springy places along streams and 

 on the borders of ponds and swamps. 



The species and varieties intergrade so completely that it is not 

 possible to separate them satisfactorily. 



This species and Vicia americana are often confused but are easily 

 separated by the fact that Vicia americana usually has 8-14 leaflets while 

 this species has 4-8. Besides the generic distinction between the styles, 

 the basal section of the stipules of Vicia americana is generally sharply 

 toothed while, if the stipules of this species are not entire or nearly so, 

 they are never sharply toothed. 



Lower St. Lawrence River to Man. and Oreg., southw. to s. Maine, Conn., 

 cent. N. Y., Ohio, and Mo. ; also in Eurasia. 



4a. Lathyrus palustris var. linearifolius Ser. Map 1274. This variety 

 has the habitat of the species but is much less frequent. 



Basin of the St. Lawrence River southw. to n. N. Y., Ind., and Minn. 



4b. Lathyrus palustris var. myrtifolius (Muhl.) Gray. Myrtle- 

 leaf Marsh Pea. Map 1275. Infrequent to very rare, mostly in the lake 

 area in habitats similar to those of the species. There are several reports 



