CTPERACK^ 410 SCIRPOS. 



high, each with an obtuse sheath at the base. Achenium roundish-obovoid, 

 rugose, punctate, surrounded with 3 or 4 scabrous bustles, and crowned with 

 a tuljercle. July. 



11. S. oBTu'sus. Willd. Headed Cluh-rush. S. capitatus. Muh. 

 Stem sulcate, subterete, 6 — 15 inches liigh ; spikelet ovoid, very obtuse, 



often nearly globose; glumes round, dark brown, with whitish margins; 

 achenium obovate, compressed, smooth, brown, invested with 6 setae as long 

 as the glumes. Shallow waters. July. 



12. S. acicula'ris. L. S. trichodes. Muh. S. capillaceus. Mx. 

 S/e//i leafless, setaceous, quadrangular, very slender, 3 — G inches high; 



spi.'cc els oblong-ovate, acute, 4 — Sfliowered ; glumes obtusish, the lowest one 

 larger and empty; adieainm obovoid, triangular, verrucose, yellow and 

 shining. Shallow waters. July. Hair Cluh-rush. 



13. S. intkrme'dius. Turf Club-rush. 



Slein slender, declining, quadrangular, furrowed, CEspitose, 2 — 3 inches 

 long; .v/;t/ie ovate-oblong ; ^/M7Ht's acute, dark brown ; style 2-cMi; achenivm 

 broad-obovate, compressed ; tubercle minute, distinct ; bristles 6, longer than 

 the fruit. In running water, forming strong, dense turf. July. 



14. S. planifo'lius. Flal-lcuvcd Cub-rush. 



Slem cffispitose, leafy at base, acutely and roughly 3-angled, 5 — 10 inches 

 high ; leaves broad-linear, flat, rough on the margin, equaling the stem ; ^pike 

 obTong-lanceol.ite, compressed, terminal, 4— 8-tiowercd ; glumes ovate-mu- 

 cronate, yellowish; bracts at'the base of the spike, cuspidate, outer ones 

 longer tiian the spike; achenium reddish brown, invested with 6 bristles 

 longer than itself. In cold, hard soils. June. 



15. S. CiT;sPiTo'sus. Scaly Cluh-rush. 



Stems ceespitose, round, sheathed at base with numerous rudiments of 

 leaves; 5/yj/tei' compressed, terminal; 2 /o?«er ff/u/^es involucre-like, as long 

 as the spike ; ach. with 6 bristles. Grows in dense tufts, 4—12 inches high. 

 Spike 4— 5-flowered, reddish brown. On the White Mts., iN. H. Bw. July. 



16. S. subterjiina'lis. Torr. 



Stem floating, furrowed, inflated, leafy below, 3 ft. long; Zeore.s very narrow ; 

 spike solitary," somewhat terminal (the stein being continued above it in the 

 form of a bract), lanceolaie ; style 2-clefl ; bristles ti. Streams, &c. Mass. Aug. 



17. S. TUBERCULO'SUS. Mx. 



Sfem coluuinar, striate, 12 inches high, leafless, sheathed at base ; spikclei 

 ovate-laticeolate; glumes very obtuse, loose; ach. somewhat triquetrous, 

 smaller than the sagittate tubercle with which it is crowned ; bristics (J, as 

 long as the tubercle. Sandy swamps. Mass. July. 

 i, 4. Ovary desUtulc ol'selce. Achenium 3-anglecl. Style trifid, not ciliate, bulbous at base. 



Glumes cariuate, somewhat 4— &-raiiked. Inflorescence terminal. Tkichelostylis. 



18. S. capii-la'ris. , • , , 

 Stem cajspitose, nearly naked, 3-angled, capillary, 4— S inches high ; leaves 



subradical. setaceous, shorter than the stem ; spikelets ovoid, 2—4, peduncu- 

 late, inner one sessile ; gUniies oblong, ferruginous, margin pubescent; ach. 

 white. In sandy fields. Aug. 



19. S. autumna'lis. . 



Stem compressed, 2-edged, ca-spitose, leafy at base, 3—10 inches high ; 

 leaves flat, linear, shorter than the stem ; vmbel compound ; involucre 2-leaved ; 

 spikelets lanceolate, acute, somewhat 4-sided, 2—3 together; glumes brown, 

 niucronate ; </c/icrtiMOT white. Wet places. July. 

 t5 Ovary desthutc of seta:. Achenium compressed. Style bifid, ciliate, bulbous at base. 



FlMBRISTYI.IS. _ . 



20. S. suBsciUARRo'sus. Muh. S. minimus. 

 Scar:e triangular, incurved, nearly naked, but 2 or 3 inches high ; spikelets 



nearly terminal, ovoid, about 3 ; involucre of 2 long, unequal leaves ; glumes 



