CTPEEACE^. (sedge PAMILT.) 555 



17. C. Griyii, Torr. Culm thread-form, wiry (6'- 12' Mgh); leaves 

 almost bristle-shaped, channelled; umbel simple, i- Grayed; spikes 5-10 in a loose 

 hold, spreading ; joints of the axis winged; scales rather obtuse, greenish-chestnut- 

 color. — Barren sands, Plymouth, Mass., to New Jersey, near the coast. 



18. C. filiciUlUiS, Viihl. Culm slender, wiry, often reclined (8' -15' 

 high); leaves linear (l"-2" wide); spikes numerous and clustered in one sessile 

 dense head, or in 1-7 additional looser heads on spreading rays of an irregular 

 umbel; joints of the axis naked; scales blunt, greenish. (C. mariscoides, Elt.) — 

 Dry sterile soil : common, especially southward. 



§4. MARISCUS, Vahl. Style 3-clefl: thf achenium triangular: stamens 3: 

 spikes 1 -few-flowered, narrow or awl-shaped, with 2 lower scales short and 

 empty, and inclined to persist on the common axis when the rest of the spike dis- 

 articulates and falls, crowded in dense heads : otherwise nearly as in the penul- 

 timate division o/*'§ 3. {Perennials with clustered small tubers at base of the culms, 

 as in the preceding division : spikes green, merely tawny with age.) 



19. C. Lancastri6nsis, T. C. Porter, n. sp. Culm (l°-20 high) trian- 

 gular ; leaves rather broadly linear; umbel of 6 - 9 mostly elongated rays ; spikes 

 very numerous in short-oblong or globular dense heads, soon reflexed, 3-6- 

 flowered, linear-awl-shaped ; the joints of the axis broadly winged ; scales oblong, 

 obtuse, twice the length of the linear-oblong achenium. — Rich soil, banks of the 

 Su.squehanna near Lancaster, Penn., Prof. Porter. — Most like the Southern 

 C. Baldwinii, Torr.; but twice the size ; the more numerous spikes 4" -5" long, 

 more linear, less pointed, on a, setaceous-bracted axis of 6" or 7" in length, 

 with longer scales and achenium, &c. 



20. C. OVUliiris, Torr. Culm sharply triangular (6' -12' high); umbel 

 1 -6-rayed; spikes (50-100) in a globular very dense head, 2 - i-flowered, oblong, 

 blunt (lJ"-2" long); joints of the axis winged; scales ovate, obtuse, a little 

 longer than the oborate-oblong achenium. — Sandy dry soil, S. New York to 

 Illinois and southward. 



21. C. retrofr^tus, Torr. Culm and leaves usually minutely downy 

 and rough on the obtusish angles (l°-3° high); umbel many-rayed; spikes 

 slender-awl-shaped, very numerous in obovate or oblong heads terminating the 

 elongated rays, soon reflexed, l-2-flowered in the middle (3" -5" long) ; scales 

 usually 4 or 5, the two lowest ovate and empty, the fertile lanceolate and pointed, 

 the uppermost involute-awl-shaped; achenium linear. (Scirpus retrofractus, i.) 

 — Sandy fields. New Jersey to Virginia, and southward. 



2. KYLLtNGIA, RottboU. Ktlungia. (PI. 1.) 



Spikes of 3 or 4 two-ranked scales, 1 - l4-flowered ; the 2 lower scales minute 

 and empty, as in Cyperus, § 4, but style oftener 2-cleft, and achenium lenticular : 

 the spikes densely aggregated in solitary or triple sessile heads. Involucre 

 3-lcaved. (Named after Peter Kylling, a Danish botanist of the 17th century) 



1. K. ptimila, Michx. Head globular or 3-lobed, whitish-green (about 

 4" broad) ; spikes strictly 1-flowered; upper scales ovate, pointed, rough on the 

 keel; stamens and styles 2; leaves linear. — Low grounds, Ohio to Illinois 

 and southward. Aug. — Culms 2' - 9' high : root annual. 



