FLORA OF THE DISTRICT OF COLUMBIA. 99 



Achene smooth; bristles longer than the achene. 



Spikeleta whitish or pale brown, in small dense cymoee heads 4. R, alba. 



Spikelets dark brown. 



Spikelets in dense globose heads 5. R. axillaris. 



Spikelets. in broad or narrow cymose heads. 



Achene ovoid, 1.2 mm. wide, rounded at base 6. R. gracilenta. 



Achene obovoid, 0.8 mm. wide, with distinct spikelike base. 



Bristles downwardly barbed 7. R. capitellata. 



Bristles upwardly barbed 7a. R. capitellata controversa. 



1. Rynchospora corniculata (Lam.) A. Gray. 



Wet sand by the Potomac at Sandy Landing, Maryland , below Great Falls: collected 

 but once. Sept. Coastal Plain, Del. southward. 



2. Rynchospora macrostachya Torr. 



Marshes along the lower part of the Eastern Branch and near Accotink Creek; infre- 

 quent. Aug.-Sept. Atlantic states and occasionally inland. (Included in R. corni- 

 culata in Britt. & Brown, Illustr. Fl.) 



3. Rynchospora cymosa Ell. 



Swales; Kenilworth and Lakeland. June-July. Southeastern states, north to N. J. 



4. Rynchospora alba (L.) Vahl. 



Open places in magnolia bogs below the fall line; frequent. July-Sept. Through- 

 out the U. S. 

 6. Rynchospora axillaris (Lam.) Britton. 



Among sphagnum in East Hyattsville Swamp. Aug.-Sept. Atlantic Coastal Plain. 



6. Rynchospora gracilenta A. Gray. 



Bogs below the fall line; small bog east of Brookland. Aug.-Sept. Atlantic 

 Coastal Plain. 



7. Rynchospora capitellata (Michx.) Vahl. 



Swales and wet spots in woods; frequent. Eastern U. S. (R. glomerata of authors.) 

 7a. Rynchospora capitellata controversa Blake. 



Wet ground; Ilolmead Swamp; near Aqueduct Bridge. Aug.-Sept. Pa. to Va. 



There is a specimen of R. fusca (L.) Ait., labeled "near Washington, D. C, Dr. 

 Geo. Vasey. " The locality is doubtful. 



12. SCLERIA Berg. Nut rush. 



Achenes smooth, white and shining. 



Culms commonly about 1 meter tall; achene globose 1. S. triglomerata . 



Culms usually not over 50 cm. tall; achene ovate 2. S. oligantha. 



Achenes reticulate or papillose. 

 Achenes reticulate; fascicles of spikelets few to several in a small panicle; axil- 

 lary fascicles slender-peduncled 4 - s - reticularis. 



Achenes papillose; fascicles of spikelets few, approximate; axillary fascicles, if pres- 

 ent, subsessile. 



Foliage glabrous 3 - S. pauciflora. 



Foliage pubescent 3*». S. pauciflora caroliniana. 



1. Scleria triglomerata Michx. 



Wet sandy woods and swales; Terra Cotta and southeastward, below the fall line; 

 frequent. June. Eastern U. S. 

 2 Scleria oligantha Michx. 



Sandy woods; represented by a single collection by Vasey labeled "Washington.., 

 D C , 1874. ? ' The specimen cited by Ward as collected at "Rock Creek above Davis's 

 Quarry, June, 1874 (Dr. Vasey)" can not be found, unless the above specimen lacking 

 data be' it. June-Aug. Southern Atlantic Coastal Plain to Tex. 



