302 
CYPERACEAE (SEDGE FAMILY) 
§ 5. Divisae Christ (sec p. ) 
Rhizomes filiform; leaves canaliculate, 1-2 nun. broad; culms obtusely angled, 
C. stenophylla , 
var. enervis. 
7. 
('. praegracilis. 
8 . ('.divisa. 
506. C. stenophylla, 
v. enervis. 
smooth, 0.5-4 dm. high; perigynia 2.5-3 mm. long 
Rhizomes stoutish, ligneous, 2-0 mm. thick; leaves flat, 2-5 mm. broad; culms 
acutely angled, scabrous toward summit, 2- < .5 dm, high; perigynia 3—4 mm. 
long. . 
Spikes 5-15, in an interrupted cylindric head 1-5 cm. long; beak of pengynnim 
one-half as long as body; western species 
Spikes 2-7, in an irregularly oblanceolate to ovoid head 1-3 cm. long; body of 
perigynium three to five times as long as beak; Atlantic species 
6. C. sTENOPHfotA Wahlenb. (slender-leaved). — Rhizomes and stolons filiform; leafy 
shoots tufted, low; the canaliculate subrigid leaves 1-2 mm. broad , curved: culms strict, slender, 
obtusely angled , smooth, 0.5-2. 5 tint, high, overtopping the leaves; spikes 5-6, 
androgynous, densely crowded in a suheontinuous ellipsoid to ovoid brown 
or ferruginous head 0.7- 1.5 cm. long, lowest bracts with awn-tips; perigynia 
ascending, coriaceous, plano-convex, thin-edged, mostly covered by the ovate 
acute scales, closely enveloping the large lenticular achene, ovate, 3-3.5 mm. 
long, definitely nerved, with a short seabrous-margined dorsally cleft beak. 
— Eurasia — Represented with us by 
Var. enervis (('. A. Mey.) Klikeuth. (nerveless). — Up to 4 dm. high; spikes 
distinct, in a definitely interrupted head; perigynia 2.5-3 mm. long, often exceed- 
ing scales, nerveless or nearly so. (C. stenophylla of Am. auth., not V ahlenb. , 
C. Eleochans Bailey) — Man. to Yuk., s. on dry plains and bluffs to la., Ivans., N.M., Utah 
and e. Oreg. Late May-July. (Asia) Fro. 506. 
7. C. praegracilis W. Boott (very slender). — Rhizomes subligneous, elongate, forking, dark- 
purple to blackish, 2-6 mm. thick, sending up scattered erect tufts of fiat seabrous-margined 
leaves 2-3 mm. broad and slender arched-ascending acutely angled scabrous 
culms 2-7.5 dm. high; spikes 5-15, androgynous, forming a linear- to lance- 
cylindric interrupted brown head 1-5 cm. long; lowest bracts awned or with 
short blade; pistillate scales ovate, acute, concealing the 
perigynia; perigynia coriaceous, plano-convex, ovate, 3-4 
mm. long, appressed-aseending, slightly nerved on the back, 
the inner face nerveless, with a serrulate heal: one-half as 
long as body; styles 2. (C. marcida Boott, not .1. F. CImel.) 507 . C. prae- 
— Low open ground and prairies, Yuk. to Mex., e. to Man., gracilis, 
n. Mich., Ia., Mo. and Olda. June, July. (S.Am.) Fig. 507. 
8. C. m visa Iluds. (separated). — Resembling no. 7, paler green; leaves 
2-5 mm. broad; culms 1-5 dm. high, firm; spikes 3-7 in an irregularly oblanceolate to ovoid head 
1-3 cm. long; perigynia ribbed on both faces, the beak several times shorter than the body. — Coastal 
sands, locai, Calvert Co., Md. May, June. (Natzd. from Eu.) Fig. 508. 
§ 6. CnoiiDoaRSiZEAE Fries (see p. ) — A single species: 
9. C. chordorrhiza L. f. (with cord-lilce roots).- Stems cord-like or wiry, 
prolonged, leaning or reclining, bearing few tufts of narrow leaves; culms terminal 
and lateral, arising from arils of shriveled leaves of preceiling year, 1-4.5 dm. 
high, smooth, obtusely angled; sjrikes 3-5, androgynous, in an ovoid, ellipsoid 
or irregularly deltoid head 0.5-1.5 cm. long; pistillate scales rounded, deep 
brown, acuminate; perigynia compressed-ovoid to subglobose, coriaceous, 2-3.5 
mm. long, nerved on both faces, with a short beak dorsally cleft. * Quag- 
mires and inundated bogs, s. Baffin I. to Alaska, s. to Nfld., e. Que., centi. 
Me., sw. Vt., centr. N.Y., n. Ind., n. Ilk, n. Ia. and Sftsk. Late May-Aug. (Eurasia) 
r . | nr- - . § 7. ArenAriae Kunth tSee p. ) 
a. Thin bolder of porigynium narrow, extending nearly to The base; inflorescences 
chiefly without leafy bracts; northern and continental species. . . b. 
b. Inner band of leaf-sheath green-nerved nearly to summit; spikes 12-25 iri a, 
^ slender head 3-7 cm. long; perigynia 2.5-5 mm. long, the beak one-fourth b 
to one-half as long as body. . 
Nodes of culm (at least the upper) exserted from leaf-sheaths; principal 
spikes nearly uniform, pale, subglobose to short-ovoid, 6—9 mm. long, 
scales obtuse to cuspidate; perigynia 2.5-4. 5 mm. long. 
1 Nodes covered by upper sheaths; inflorescence more continuous above, 
508. C. divisa. 
509. 
C. chordor- 
rhiza. 
Fig. 509. 
7# 
10. C. Sartwellii. 
i 
