CONTRIBUTIONS TO THE FLORA OF IOWA. 73 



Polygonum tenue, Michx. (No. 683"), has a number of times been 

 reported with specimens from various parts of the State, but has always 

 heretofore proved to be a small form of the abundant F. raniosissimum. 

 The true P. tenue is, without doubt, a rare plant in Iowa. The region 

 from which the present specimens come, the extreme northwestern 

 corner, is geologically and botanically very unlike the rest of the State. 



Potamogeton pusillus, L. (No. 783"), is said by Mr. Morong to be 

 the typical form, but what has generally been called var. vulgaris. 



Sehedouuardus Texaiius, Steud. (No. 950*^) is described in Gray's 

 Manual under the name of Lepturus paiiiculatus, Nutt. See "North 

 American Oenera of Grasses," by F. L. Scribner, in Bull. Torr. CI., IX., 

 134, and X., 8; also, "Grasses of United States," by George Vasey, 

 1883, p. 32. 



Agropyruiii violaeeuui, Vasey (No. 95 2^*^, is described in Gray's Man 

 ual under the name oi Triticuin violaeeuni, Horn. See \^asey's "Grasses 

 of the United States," 1883, p. 45. 



Isoetes melanopoda. J. Gay (No. 980), was collected near Clinton by 

 Dr. George Vasey in 1862, and specimens are now in his herbarium in 

 Illinois. They were determined by Dr. Engelmann. No other speci- 

 mens are known to have been collected in the State. The plants, 

 being grass-like in appearance, are doubtless overlooked. The Iowa 

 specimen is cited in Engelmann's " Isoetes of North America," p. 3. 



Afarsilia vestita, Hook. & Grev. (No. 983), is given solely on the au- 

 thority of "Wood's Class-book of Botany" (editions of i860 and 1869), 

 p. 810, which says that it was "sent from Iowa, near the Mississippi 

 River, by Dr. Cousens." Probably no other specimens than those re- 

 ferred to have been collected in the State. The citation of Iowa under 

 M. vestita in Underwood's "Our Native Ferns and their Allies," p. 115, 

 is on the same authority, as I am informed by the author. In Wood's 

 "Botanist and Florist" (1870), p. 360, a later publication than the "Class- 

 book," we find that Iowa is credited with M. uuci?iata, Br., with no ref- 

 erence to M. vestita of the "Class-book," or to Dr. Cousens' specimens. 

 Inquiry at the College of Pharmacy, in New York City, where Prof. 

 Wood's herbarium is now deposited, discloses the unfortunate fact that 

 many of the specimens were considered worthless, when the herbarium 

 recently came to be mounted, and were destroyed, and that as the 

 specimens in question cannot be found, they were doubtless among the 

 discarded ones. We have therefore no direct way of determining with 



[Pboc. D. a. N. S., Vol. IV.] 10 [Sept. 4, 1884.] 



