FERNALD. — ELEOCHARIS OVATA. 489 



between the two. This low form, more common in New England than 

 the tj'pical erect E. ovata, is doubtless the Silesian variety Beuseri of 

 Uechtritz. From the description alone of Terracciano's var. hutnifusa^ 

 our plant may be the same as that Italian form. No specimens of the 

 latter have been seen, and as the New England plant is clearly identi- 

 cal with the more northern var. Heuseri, Uechtritz, that name will here 

 be taken up. 



This flexuous dark-headed plant is not the only anomalous form long 

 referred to Eleocharis ovata. A tall northwestern plant, 7 or 8 dm. high, 

 has been considered by Mr. C. B. Clarke as a variety of this species. 

 Aside from its unusual size, this plant is well characterized by the re- 

 markable broadly obcordate tubercle (Figs. 11, 12), which is not at all 

 compressed and fully half as high as the achene itself Other north- 

 western plants, however, connect this extreme form directly with the 

 typical E. obtusa, so that it seems undoubtedly an extreme variety of 

 that species. Another striking form which an abundance of material 

 shows to be in reality an extreme variation of E. obtusa is a slender 

 somewhat depressed plant of the east. This plant (Figs. 13, 14), with 

 capillary erect or generally decumbent or spreading culms mostly a deci- 

 meter or less (very rarely 2 dm.) high, is frequent in damp sand or in 

 exsiccated places in New England and other eastern States. The short 

 few-flowered heads are from 2 to 5 mm. long, and the oblong obtuse scales 

 are slightly more spreading than in the true E. obtusa. The achenes, how- 

 ever, though a little smaller, are not distinguishable from those of that 

 species, and occasional specimens occur which might equally well be 

 referred to either form of the plant. For this reason, although the plant 

 with capillary short culms seems habitually very distinct, it is here treated 

 as a variety of E. obtusa. The smaller achenes of this low plant are about 

 as high as those of the European E. ovata, but they are readily distin- 

 guished from that species by their greater breadth and by their tubercles. 



Some other plants which have been associated in our herbaria with 

 Eleocharis ooata apparently have less affinity with that species. E. dian- 

 dra, Charles Wright (Figs. 53 to 58), has already been briefly discussed. 

 Prior to publishing the species himself, Mr. Wright sent specimens to Dr. 

 Gray who then considered the plant a " pretty good species," and gave it 

 a provisional (though never published) name in the herbarium. In 1883 

 Mr. Wright described his plant, distinguishing it by a number of appar- 

 ently constant characters from E. obtusa. In his "Genus Eleocharis in 

 North America," however, Dr. Britton treated the plant as a probable 

 form of the older species ("ovata"). In the subsequent edition of Gray's 



