86 



CYPERACE.E. 



3. FIMBRISTYLIS Vahl. 



Annuals or perennials. Stems leafy below. Spikelets umbellate 

 or capitate, terete, subtended by a 1 to many-leaved involucre. 

 Stamens 1 to 3. Bristles none. Style 2 to 3-cleft, its base much 

 swollen, the whole falling away from the achene at maturity. 

 Achene lenticular or triangular. (Latin timbri, thread-like, stylus, 

 style.) 



Spikelets umbellate, solitary 1. F. miliacea. 



Spikelets elusteied . . . 2. F. apus. 



1. F. miliacea Vahl. Annual (?); umbel diffusely compound; 

 spikelets sub-globose, about 1 line long; style 3-cleft; achene acutely 

 triangular, muricate-tuberculate. 



Keported as introduced at San Francisco. 



2. F. apus (Gray) Wats. Annual; spikelets in nearly sessile 

 clusters, lanceolate, 2 lines long; style 2-cleft; achene lenticular, 

 obovate, faintly tuberculate. 



Clear Lake, Bolander. 



4. SCI R PUS L. Club-rush. Bulrush. 

 Annuals or perennials. Stems leafy or the leaves reduced to mere 

 sheaths at base. Spikelets terete or somewhat flattened, solitary or in 

 heads spikes or umbels, subtended by an involucre of 1 to several 

 leaves or the involucre obsolete. Bristles 3 to 6, barbed, ciliate, or 

 obsolete. Stamens 2 to 3. Style 2 to 3-cleft, not swollen at the base, 

 deciduous or its base persistent on the achene. Achene triangular, 

 lenticular or obovoid. (Latin scirpus, bulrush.) 



Stems low and slender; inflorescence terminal; spikelet mostly solitary; bristles 

 obsolete.— Sub-genus Isoi.epis Benth. 

 Stems 2 to 6 in. high; bractlets obtuse or mucronate; involucral bract 1 to 



3 lines long 1. S. riparius. 



Stems 1 to 3 in. high; bractlets acute, shortly beaked, strongly keeled; 



involucral bract 5 to 9 lines long 2. S. carinatun. 



Stems tall and stout; spikelets in clusters, umbels or panicles; bristles retrorsely 

 barbed or ciliate or rarely obsolete.— Sub-genus Eu-sorpcs Benth. 

 Inflorescence Apparently lateral; involucre of a single erect bract. 



Stem terete or nearly so, leafless or nearly so; spikelets umbellate . . . . 



3. S. lacustris 

 var. occidentodis. 



Stem triquetrous or wing-angled, leafless or with a single short leaf at 

 base; involucral bract 1 in. or less long; spikelets densely clustered. 



4. S. Olneyi. 



Stem triangular, somewhat leafy; involucral bract 1 to 4 in. long; spike- 

 lets densely clustered 5. S. Americanus. 



Inflorescence terminal; involucre of several spreading, foliaceous bracts. 



Spikelets 5 to 8 lines long, few, sparingly umbellate or in a sessile cluster, 

 dark brown 6. S. robustus. 



Spikelets \y 2 to 2 lines long, numerous, in a compound or decompound 

 panicle, greenish or lead-colored 7. S. microcarpus. 



1. S. riparius Spreng. Slender Clttb-RUSH. Annual; stems 

 tufted, very slender, 2 to 6 in. high, sheathed at base; upper sheath 

 often bearing a short slender leaf; involucral bract 1 to 3 lines long; 

 spikelet solitary, oblong-ovate, 1£ to 2£ lines long, mostly less than 



