260 PATAGONIAN EXPEDITIONS : BOTANY. 



b2. Culms numerous, cespitose ; sheaths mucronate. Spike ovate-oblong to linear. Scales 



black-purple with green keel. Setae none. ccrnuus. 



3. Culm filiform. Spike oval, compressed. Scales with purplish margin. Setae 6, two of 



them shorter than the striate achene. retroflexus. 



Az. Cespitose. Culms filiform, i -leaved at base, glabrous. Spikes 1-2 (rarely 3-4). Invo- 

 lucre i -leaved, exceeding the spikes. Scales with white sides having a purple spot. 



setaceus. 

 AT,. Unequally umbelliform. 



b. Root creeping. Culm tall, leafy below ; leaves flat, as long as the culm. Involucre 3- 

 4-leaved. Spikes several, oblong. Scales ovate, bifid, midnerve mucronate-awned. 

 Setae 26, barbed, or none. maritimus. 



b2. Cespitose, tall. Culm filiform, leafy below. Leaves setaceous. Involucre 3-leaved, 



shorter than the depauperate, 3-5 -leaved umbel. jnncoides. 



3. Culm subtrigonal, striate. Involucre 2 -leaved, the outer pungent. Umbel many-rayed. 



Scales elliptical-round, mucronulate. Setae 2, barbed. riparius. 



64. Culm leafless, 25 mm. high. Spikes 1-3 in a bracted head. Setae 6, retrorsely barbed. 



des cr ticola. 

 AT,. Spikes several, bract i, exceeding them. Scales brown. 



b. Culms sharply 3-angled. Scales awned. Setae 2-3, retrorsely barbed, not exceeding the 



plano-convex achene. americamis. 



l>2. Culms slender, flattened above. Scales acute. Setae 3, retrorsely barbed, not half as 



long as the plano-convex achene. nevadensis. 



A^. Spikes in a decompound umbel, with unequal rays. Bracts 3-4. Scales recurved mu- 

 cronate. Setae 6, retrorsely barbed. glaucus. 



i. S. ALBIBRACTEATUS (Nees & Mey. sub Eleocharis] O. Ktze. 



Root creeping. Culms very short, 25-40 mm. long, setaceous, striate, 

 tetragonal, recurved. Spike ovate, few-flowered ; its scales ovate, obtuse, 

 carinate, the sides rusty-red, or all straw-white ; the lowest sterile. Setae 

 6, whitish. Style trifid. Achene lenticular, punctate-striate, with yellow 

 base, crowned by the persisting style. 



(Peru) ; Patagon. ; N. and E. Fuegia. 



2. S. AMERICANUS Pers. Three-square. 



Perennial by long rootstocks. Culm triquetrous, erect, to one meter 

 tall. Leaves 1-3, narrow, keeled, shorter than the culm. Spikelete ob- 

 long-ovoid, in heads, as if. lateral. Involucral leaf slender. Scales 

 broad-ovate, brown, emarginate, awned. Setae 2-6, retrorsely barbed. 

 Stamens 3. Achene plano-convex. 



W. Patagon., wet elevations by Rio Aysen. 



