412 GYPERAGEM. [Scmrus. 



* Stem leaf ess or nearly so. Cymes leafless. 



1. S. lacus'tris, L. ; stems terete usually leafless, cymes terminal 

 branched longer than the bracts, branches stout, spikelets solitary or 

 clustered, glumes obtusely 2-lobed mucronate ciliate. Bulrush. 



Lakes, flitches, and marshes, N. to Shetland; Ireland; Channel Islands; 

 fl. July-Aug. Stems 1-8 ft., spongy, as thick as the thumb or less, base 

 sheathed. Leaves 0, or short flat and keeled in still water, or long and 

 strap-shaped in streams. Cyme lateral at first, then expanding and over- 

 topping the stern ; branches few, -3 in., strict, stout. Spikelets 1-6, j g 

 in., sessile, cyiindric in flower, ovoid in fruit, red-brown. Glumes mucronate 

 or awned. Bristles 4-6, shorter than the broad nut. DISTRIB. Arctic, 

 temp, and trop. regions. 



S. LACUS'TRIS proper : stems terete green, leaves often floating, glumes gla- 

 brous, anther-tips ciliate, nut 3-gonous. 



Sub-sp. S. TABERNJEMONTA'NI, Gmel.; stems terete glaucous, glumes scabrid, 

 anther-tips glabrous, nut compressed. S. ylau'cus, Sm. Usually near the 

 sea, from Fori'ar and Dumbarton southd. ; Ireland ; Channel Islands. 



Sub-sp. S. CARINA'TUS, Sm. ; stems green obtusely 3-gonous above, glumes 

 smooth, anther-tips glabrous, nut compressed. Tidal rivers, Middlesex, 

 Kent, Cornwall. 



2. S. tri'queter, L. ; stem 3-quetrous usually leafless, cymes lateral, 

 branches short stout, spikelets solitary or few elongate ovoid, glumes' 

 obtusely 2-lobed mucronate. 



Muddy tidal rivers; Middlesex and Sussex to Cornwall ; fl. Oct. Eootstock 

 slender. Stems 1-3 ft., strict, spongy, concave on one side. Leaves 0, or 

 very short on the upper sheath. Spikelets in sometimes sessile clusters. 

 Glumes obovate, brovvn, smooth. Anther-tip glabrous. Bristles 2-6. Nut 

 obovoid, 3-gonous, smooth, shining. DISTRIB. From Denmark southd. 

 (excl. Spain, Greece, Turkey), E. Asia, Africa, America, Australia. 



3. S. pun'gens, Vahl ; stems 3-quetrous, leaves 2-3 linear, spikelets 

 lateral sessile, glumes ovate acutely 2-lobed mucronate. S. Roth'ii, Hoppe. 

 Sandy banks of St. Ouen's Pond, Jersey ; fl. June-July. Habit of S. tri'queter, 



but smaller, more slender, 6-18 in. ; leaves 4-6 in., channelled, keeled ; 

 spikelets in., sessile; glumes red-brown ; anther-tips acute ; bristles 1-2 ; 

 nut obovoid, pale. DISTRIB. ~W. Europe, from Denmark southd. 



** Stem 3-gonous, leafy. Cymes terminal, leafy. 



4. S. marit'imus, L. ; leaves channelled, cymes corymbose, spikelets 

 few cyiindric red-brown, glumes acutely 2-lobed awned. 



Salt marshes from Eoss and Skye southd. ; Ireland ; Channel Islands ; fl. 

 July-Aug. Eootstock often tuberous. Stems 1-3 ft., tufted, rigid, leafy 

 below. Leaves often in. broad, elongate, keeled, dark green. Spikelets 

 J-l in., brown, peduncled or sessile; bracts |-1 ft.; glumes glabrous or 

 pubescent. Bristles 1-6. Nut compressed or 3-gonous, truncate, dotted, 

 shining.- DISTRIB. Europe (Arctic), N. Africa, W. Siberia, N.W. India, 

 N. America. 



