Part 181 (1/2)

[++][++] _Perennial, propagating by corm-like tubers from the base; spikelets narrow, ac.u.minate, often teretish; scales oblong-lanceolate; achene linear-oblong._

18. C. strigsus, L. Culm mostly stout (1--3 high); most of the rays of the umbel elongated (1--5'), their sheaths 2-bristled; _spikelets 5--25-flowered_, spreading; scales several-nerved, much longer than the achene.--Damp or fertile soil, Canada to Fla., west to Minn., Tex., and the Pacific. Very variable in the number and length of the rays of the simple or compound umbel, and in the size of the spikelets (2--6 or even 12” long), more or less densely crowded on the axis.

-- 4. DICLiDIUM. _Style 3-cleft; spikelets narrow, terete or nearly so, few--many-flowered, the scales closely appressed and the broad wings of the jointed rhachis enclosing the triangular achene._

19. C. specisus, Vahl. Culm stout, _mostly low_ (5--20' high); _rays of the simple or compound umbel mostly all short and crowded; spikelets 10--20-flowered, yellowish-brown_ at maturity (3--7” long), the short joints of its axis winged with very broad scaly margins which embrace the _ovate triangular achene; the scales ovate, obtusish, imbricately overlapping_. (C. Michauxia.n.u.s, _Gray_, Manual; not _Schultes_.)--Low grounds and sandy banks, N. Eng. to Fla., west to Minn. and Tex.

20. C. Engelmanni, Steud. Resembles n. 19; but the _spikelets more slender_ and terete, _somewhat remotely 5--15-flowered_, the zigzag joints of the axis slender and narrowly winged, and the oblong or oval broadly scarious _scales proportionally shorter_, so as to expose a part of the axis of each joint, _the successive scales not reaching the base of the one above_ on the same side; achene oblong-linear, very small.--Low grounds, Ma.s.s. to Wisc. and southward.

-- 5. MARiSCUS. _Spikelets 1--4-flowered, subterete, usually in dense heads; scales oppressed, several-nerved, the lower empty and often persistent after the fall of the rest of the spikelet; joints of the rhachis winged, enclosing the triangular achene. Perennial._

[*] _Spikelets slender and ac.u.minate, more or less refracted in usually close umbelled spikes.--Connecting with -- 4._

21. C. Lancastriensis, Porter. Culm (1--2 high) triangular; _leaves rather broadly linear_; umbel of 6--9 mostly elongated rays; _spikelets very numerous in short-oblong close heads_, soon reflexed, of 3--6 narrow scales, the upper and lower empty, twice the length of the linear-oblong achene, which is nearly 1” long.--Rich soil, Penn. and N. J. to Ala.

22. C. retrofractus, Torr. Culm and leaves usually minutely downy and rough on the obtusish angles (1--3 high); umbel many-rayed; _spikelets slender-awl-shaped_, very numerous in obovate or oblong heads terminating the elongated rays, _soon strongly reflexed, 1--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; achene linear, 1” long.--Sandy fields, N. J. to Fla. and Tex.

23. C. refractus, Engelm. Culm 1--2 high; rays usually more or less elongated; spikelets very slender, in rather loose heads, divaricate or more or less reflexed, 2--4-flowered; achene linear, 1” long.--N. J.

to N. C. and Mo.

[*][*] _Spikelets very short, blunt, in densely compacted globose or cylindrical heads._

24. C. ovularis, Torr. Culm sharply triangular (6'--2 high); umbel 1--6-rayed; _spikelets_ (50--100) in a _globular head, 3-flowered, oblong, blunt_ (1--2” long); scales ovate, obtuse, a little longer than the ovate-oblong achene.--Sandy dry soil, southern N. Y. to Fla., west to Ill., Ark., and Tex.--Var. ROBuSTUS, Boeckl., is a form with large heads (4--8” long), the spikelets 3--4-flowered. (C. Wolfii, _Wood_.)--Ill. to Ark., and southward.

25. C. Torreyi, Britton. Like the last, but the _heads cylindrical or oblong, spikelets usually 2-flowered_, and _achene linear-oblong_.--L.

Island to Fla., west to Tex.

2. KYLLiNGA, Rottboell. (Pl. 1.)

Spikelets of 3 or 4 two-ranked scales, 1--1-flowered; the 2 lower scales minute and empty, as in Cyperus, -- 4, but style oftener 2-cleft and achene lenticular; spikes densely aggregated in solitary or triple sessile heads.--Culms leafy at base; involucre 3-leaved. (Named after _Peter Kylling_, a Danish botanist of the 17th century.)

1. K. pumila, Michx. Annual; culms 2--9' high; head globular or 3-lobed, whitish-green (about 4” broad), spikelets strictly 1-flowered; upper scales ovate, pointed, rough on the keel; stamens and styles 2; leaves linear.--Low grounds, Ohio to Ill., south to Fla. and Tex. Aug.

3. DULiCHIUM, Pers. (Pl. 1.)

Spikelets many- (6--10-) flowered, linear, flattened, sessile in 2 ranks on axillary solitary peduncles emerging from the sheaths of the leaves; scales 2-ranked, lanceolate, decurrent, forming flat wing-like margins on the joint below. Perianth of 6--9 downwardly barbed bristles.

Stamens 3. Style 2-cleft above. Achene flattened, linear-oblong, beaked with the long persistent style.--A perennial herb, with a terete simple hollow culm (1--2 high), jointed and leafy to the summit; leaves short and flat, linear, 3-ranked. (An alteration of _Dulcichinum_, an old name for a species of Cyperus.)

1. D. spathaceum, Pers.--Borders of ponds, N. Scotia to Fla., west to Minn. and Tex. July--Sept.

4. ELEoCHARIS, R. Br. SPIKE-RUSH. (Pl. 3.)

Spikelet single, terminating the naked culm, many--several-flowered.

Scales imbricated all round in many (rarely in 2 or 3) ranks. Perianth of 3--12 (commonly 6) bristles, usually rough or barbed downward, rarely obsolete. Stamens 2--3. Style 2--3-cleft, its bulbous base persistent as a tubercle jointed upon the apex of the lenticular or triangular achene.--Leafless, chiefly perennial, with tufted culms sheathed at the base, from matted or creeping root-stocks; flowering in summer. (Name from ????, _a marsh_, and ?a??? _to delight in_; being marsh plants.)

-- 1. _Spikelet terete, hardly if at all thicker than the spongy-cellular culm; scales firmly persistent; style mostly 3-cleft; bristles 6 (rarely 7), firm or rigid, mostly barbed downward, equalling or surpa.s.sing the triangular or lenticular achene._

[*] _Spikelet linear or lanceolate-awl-shaped, few-flowered; scales (only 3--9) few-ranked, convolute-clasping the long flattened joints of the axis, lanceolate, herbaceous (green) and several-nerved on the back, and with thin scarious margins._