1904] Chase, — Allies of Scirpus lacustris 71 



Tesemini, Kootenai Co., specimen with slender culms 2 m. high, 

 spikelets 23 in number, slightly larger than those of the other speci- 

 mens, scales with scabrous midrib, otherwise glabrous ; achenes 

 very immature, bristles 2-4 very fragile as in the other speci- 

 mens, doubtless a form of this species {Sandberg 687). 



Scirpus heierochaetus is distinguished from S. validus and S. 

 occidentalls by the 3-cleft style, by the triquetrous achene, by the 

 fragile unequal bristles fewer and shorter, and by the glabrous scales. 

 From S. lacustris L., to which it is closely allied, it is distinguished 

 by the terete involucral bract, solitary spikelets, and fragile unequal 

 bristles fewer and shorter. Apparently rare; the above specimens 

 all lack rootstocks. It is worthy of note that four of the above 

 specimens bear some note by the collector of variation from S. 

 lacustris so called. 



Scirpus Californicus (C. A. Meyer) Britton, 111. Fl. i: 267 (1896). 



Elytrospermum Ca/ifornicum C. A. Meyer, Mem. Acad. St. Pdtersb. 

 (V.) i: 201, pi. 2 (1831). 



This remaining species of the lacustris group in this country has 

 been recognized as distinct, and is so easily determined by its 

 aristate scales and broad, dark red bristles plumose below, that it 

 needs no delineation here. 



The greater number of specimens examined were immature. In 

 Scirpus, as in the other genera of Cyperaceae it is very important 

 that plants be collected at maturity. 



Thanks are due the Gray Herbarium, National Herbarium, and 

 herbaria of the New England Botanical Club and of the Field 

 Columbian Museum, for the loan of specimens, and to Prof. C. V. 

 Piper for helpful criticism. 



Division of Agrostology, Department of Agriculture, Wash- 

 ington, D. C. 



Explanation of Plates 52 and 53. 



a. Scirpus validus Vahl [A. Chase 1136, Chicago). 



b. Scirpus lacustris L. {Reinsch^ Erlangen). 



c. Scirpus occidentalis (Watson) Chase (c. A. Chase 1628, South Chicago, 



ilhistrating Lake Micliigan and New England form ; cc. LeibcrgSG^, 

 Oregon, illustrating the western form). 



d. Scirpus heierochaetus Chase {Brexver d- Chickering; Havana, N. Y. 



type specimen). 

 Corresponding parts drawn on the same scale ; inflorescence natural size ; 

 spikelet X 5 diam., achene with cross section, and scale X 10 diam. 



