490 PROCEEDINGS OF THE AMERICAN ACADEMY. 



Manual it is given only minor recognition, as a probable form of E. 

 ^•ovata,'^ and in the Illustrated Flora it is not even mentioned. Though 

 the plant is as yet known only from a limited area in the Connecticut 

 valley, its structural characters distinguish it from E. ovata and E. obtusa 

 quite as clearly as do those of the now well recognized E. Engelmanni. 



An Arkansas plant (Figs. 27 to 29) sent by Prof. F. L. Harvey to 

 the late William Boott has been passing as a form of E. obtusa. In 

 habit the plant resembles both that species and E. diandra, but its cap- 

 illary culms are as fine as in the most slender specimens of the latter 

 species. The heads, however, are not broad as in those species, but 

 lanceolate and acute, 5 to 8 mm. long. The very pale ascending scales 

 are lanceolate or oblong-lanceolate and acuminate. The achene, though 

 not unlike that in the smallest form of E. obtusa^ is shorter and broader 

 than is usual in that plant, and the tubercle is hardly so depressed. 



Another plant (Figs. 45 to 52) which has been included in the com- 

 plex called Eleocharis ovata is a low but erect plant of the Northwest, 

 occurring from the Coeur d'Alene valley southwestward through Oregon 

 to the northern Sierra Nevada of California and extending eastward to 

 the northern prairie region. The original specimens sent by Mrs. Pul- 

 sifer Ames from the Sierra Nevada in 1876 were referred by Dr. Gray 

 to E. palustris, and subsequently by Dr. Watson to E. obtusa. Similar 

 specimens, if not from the identical collection, were sent by Mr. Lem- 

 mon to William Boott, who pronounced them E. obtusa, as he did also a 

 plant sent a year later by Mr. Howell from Multnomah Co., Oregon. 

 Excellent material of essentially the same plant recently distributed by 

 the National Herbarium from the Coeur d'Alene valley in Idaho is la- 

 belled E. ovata, as are also exceptionally large specimens collected by 

 Professor Macoun in Manitoba. Though habitally somewhat suggesting 

 the common E. obtusa, this northwestern annual plant has narrower 

 looser-flowered acutish heads varying from ovate-lanceolate to oblong- 

 lanceolate, and the narrower chestnut-tinged scales are acutish and more 

 spreading. The achenes, though not unlike those of E. obtusa, are capped 

 by more compressed tubercles resembling those of E. Engelmanni. The 

 bristles, too, are like those of the latter species, about equalling the 

 achene or much shorter, not exceeding it as in E. obtusa. In the shape 

 of its spike and tubercle, then, and in its bristles, the northwestern plant 

 IS more like E. Engelmanni than E. obtusa. From that species it differs 

 in its more ovoid head, and darker more acutish and spreading scales. 

 E. Engelmanni, as ordinarily recognized, is a species of low altitudes, — 

 primarily in the middle States, and rarely reaching the Atlantic seaboard. 



