228 UNITED STATES AND MEXICAN BOUNDARY. 



Eleochaeis equisetoides, Tott. Cyp. p. 296. E. Elliotti, Dietr. Spec. 2^ p. 82, ex Kunth. 

 Scirpus equisetoideSj EIL SK 1, p. Y9. In water^, borders of the San Felipe. Near the Rio 

 Grande, October ; Bigeloiv. The nodes of the culm, especially on the upper part^ are much 

 more closely approximated than usual. 



. Eleochakis cellulosa, Torr. Cyp. p. 298. Boggy banks of the Koyo Zaquete, September ; 



ScJwtt. Kio ColezOj Texas ; Tlmrber. Rutenville in the same State ; Wright. We have speci- 

 mens also from Key West, collected by Mr. Blodgett. 



Eleocharis palustris, B. Broivn^ Prodr. p. 224 : Torr. Cyp. p. 299. Alluvial soils, in over- 

 flowed places, from the Rio Grande to California. A variety with spikes nearly an inch long, 

 and with only rudimentary bristles at the base of the nutlets, was found by Dr. Bigelow near 



San 



YIO, ^12, 1934, 1957, and 1960, Wright 



Eleochariu obtusa, Schultesy Mant. 2^ p. 89 ; Torr. Cyp, p. 303. Western Texas ; Wright. 



Eleocharis capitata, B, Broicn^ Prodr. p. 225 ; Torr. Cyp. p. 305. On the Eio Coleto, Texas; 

 Thurher. (Nos. 1932 and 1933, Wright.) 



Eleocharis rostellata, Torr. Fl. N. Yorh^ 2, p. 347. Scirpus rostellatus, Torr. Cyp. p. 318. 



Pedro, Pinta, etc. Santa Eita del Cobra, New Mexico ; Bigelow. San Bernardino^ Sonora ; 



Thurher. (Nos. 1931, 1934, and 1956, Wright.) 



Eleocharis tenuis, SchuUes^ var. /9, Torr. Cyp. p. 310. Western Texas; Wright^ (No- 713.) 



In old spikes the scales are deeply bifid, and the divisions acute. The nutlets are pyriform^ of 

 a brownish yellow color, very obscurely triangular, with three slightly elevated lines at the 

 angles. The bristles are only rudimentary, 



Eleocharis arenicola, Torr. in Engelm. & Gray^ PI. Lindh. p. 30. Western Texas ; Wright^ 

 (No. 1958 and 1959.) The plant is much taller (12-15 inches) than the original specimens 



r 



and the bristles are barely as long as the nutlets ; but in other respects there is no difierence. 



Eleocharis acicularis, R. Brown^ Prodr. 1, p. 224 ; Torr. Cyp. p. 308. Western Texas to 

 California. Wright's No. 1937 is a small form, growing on wet ground. 



} 



Gray^ in Engelm. & Gray^ PI. Lindh. p. 30, (adn.) (h Man 



Mines. New 



San Bernardino, Sonora; Thurher. (No. 1964, W't 



sometimes almost 



The style is sometimes 3, and even 4 -cleft. 



Scirpus PUNGENS, Vahl^ Enitm. 2^ p. 255 ; Gray^ Man. I. c. Frontera, Texas; Parry. (N 

 1941 and 1963, Wright.) The spikes are oblong or 

 is more frequently 3- than 2-cleft. 



Scirpus lacustris^ i/^w.; Torr. Cyp. p. 321. S. validus, Vahl^ Enum. 2, p. 268. S. acutus, 

 MuhL Gram. p. 33. On the Eio Grande and its tributaries, from El Paso to San Jose, and 

 westward to California- On the valley of the Sacramento, Dr. HulsC;, there are thousands of 

 acres covered with this plant, and of the height of 9 or 10 feet. It is called Tule or Giant rush. 

 It varies much in the size of the panicle. The perigynous bristles are mostly narrow and 

 retrorsely hispid, but sometimes broad and retrorsely or horizontally plumose. These characters 

 are not constant, there being intermediate forms. Bentham refers No. 2021 of Hartweg's Cali- 

 fornian collection to S. riparius, Presl^ which Kunth regards as identical with Elytrospermum 

 Californicum, O. A. Mey. ; which again is the same as the earlier Malacochete of Nees. In our 

 specimen of Hartweg's plant there are four plumose bristles, while Meyer states that there are 

 but two in his Elytrospermum. The number of these organs is, however, by no means constant 

 in this genus, and in every other respect Elytrospermum resembles the form of Sc. lacustris with 



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