ORDER CXXXVI. COMMELYNACE.E 8PIDERWORT-FAM. ORDER CXXXIX. CYPERACE.E. SEDGE-FAM. 209 



ORDER CXXXVI. Commelynacese. Spider- 

 ivort-family. 



1. TRADESClNTIA. 

 Flowers regular. Sepals persistent Petals all similar, ses- 

 sile. Stamens perfect, with bearded filaments. Anthers reni- 

 forui. Capsule 2 3-celled. 



1. T. Virginica. 



Spiderwort. 



Stem nearly or quite erect, simple or branching, jointed, leafy; leaves linear- 

 lanceolate, crennto, sheathing at base, tapering to an acute point, at length 

 elongated and reflexed. A handsome plant, with bright blue flowers, native in 

 Western N. York and farther West, but frequent in cultivation. Stem erect, 

 12 ft. high, mucilaginous. May Aug. Per. 



ORDER CXXXVII. Xyriddcee. Yellow-eyed 

 Grass-family. 



\. XYRIS. 



Flowers in dense, terminal heads, each inclosed in a scale-like 

 bract Sepals 3; 2 lateral ones persistent, the larger one in- 

 closing the yet-unopened corolla, and finally deciduous with it. 

 Petals with more or less united claws. Stamens 3, on the claws 

 of the petals, alternating with 3 sterile ones. Style 3-cleft 

 Capsule 1-celled, with 3 parietal placentae. 



1. X. bulbosa. 



Yellow-eyed Grass. 



Scape slender, more or less bulbous at base, somewhat 3-angled, compressed 

 above, very smooth, Ht length twisted ; leaves much shorter than the scape, 

 narrow-linear; flowers in an ovoid-globose head ; stamens projecting from the 

 yellow, ovate, crenate, spreading petals. A curious, rush-like plant, 4' 10' 

 high. Rather common, especially in marshy grounds near the coast July 

 Sept. 



ORDER CXXXVIII. Eriocaulonaceae. Pipe- 

 wortrfamtty. 



1. ERIOCAtTLON. 



Flowers monoecious, collected in a dense head ; central ones 

 sterile, with 4 6 stamens ; outer ones fertile, with 1 style and a 

 2 3-parted stigma. Perianth double, persistent Sepals 2 3. 

 Corolla in the sterile flowers tubular ; in the fertile flowers con- 

 sisting of 2 3 separate segments. Capsule 2 3-celled, Cells 

 1 -seeded. 



1. E. septangulare. 



Pipewort. 



Smooth ; aquatic ; scape smooth, about 7-furrowed ; leaves radical, linear, 

 subulate at extremity, pellucid, in tufts at the bottom of the water; flowers 

 white, in dense, hemispherical heads ; outer scales or bracts obovate, obtuse. 

 An aquatic of very simple cellular structure, common in the edges of ponds, 

 with a slender, erect scape, arising from a tuft of leaves at bottom, and bearing 

 the white, dense head of flowers at the top. The length of the scape varies 

 with the depth of the water, from a few inches to several feet in length. July 

 Aug. 



ORDER CXXXIX. Cyperaceae. Sedge- 

 family. 



SYNOPSIS OF THE GENERA. 

 A. Flowers all perfect. 



* Flowers arranged in i IK- spikelets in 2 rows. 



1. CYPERITS. Spikelets in loose or dense clusters, usually arranged in an ir- 

 regular, simple or compound involncrate umbel, rarely a globose head. 



2. DULJCIHUM. Spikelets in loose, solitary, axillary spikes. 



** Flowers not arranged in very regular rows in 

 the spikes or spikelets. 



8. ELE6rn\Kis. Spike single, terminal. Perianth consisting of about 6 

 bristles. Stamens 8. Style bulbous at base. Acheniiim tuberculate. 



4. SciRrirs. Spikes single or clustered, and either lateral or terminal. Peri- 

 anth consisting of 36 bristles surrounding the ovary, and scarcely if at all ex- 

 ceeding the glume. Stamens 8. Styles not bulbous at base. 



27 



6. ERidpHORUM. Spikes in irregular umbels, rarely solitary. Perianth con- 

 sisting of many, rarely of only 6 long, woolly bristles, much exceeding the 

 glumes. 



6. FIMBR'ISTYLTS. Spikes in irregular, involucrate umbels. Perianth of 

 bristles none. Stamens 8. Style 2 3-cleft, not bulbous at base. 



.R Flowers monoecious, dioecious or polygamous. 



1. KIIYNCHOSPORA. Lower flowers of the spike pistillate, uppermost 

 rtamtnate; Intermediate perfect. Perianth consisting of 6 bristles. Achenium 

 with a short broad tubercle. 



8. CLADIUM. Lower flowers of the spike empty ; 1 or 2 of the rest usually 

 staminate aud barren, the terminal 1 perfect and fertile. Perianth of bristles 

 none. Achenium without a tubercle. 



9. CAREX. Flowers monoecious or rarely dioecious, the 2 kinds either 

 in separate spikes, or in separate parts of the same spike; glumes 1 -flowered. 

 Fruit consisting of an inflated bag or sac, containing the achenium. 



1. CYPERUS, 



Spikelets few, many-flowered, in loose or dense, somewhat 

 capitate clusters, which usually form an irregular, simple or com- 

 pound umbel. Glumes arranged in 2 rows, decurrent at base. 

 Stamens 1 3, usually 3. Style 2 3-cleft Achenium lenticular 

 or triangular. Culm triangular, with 1 3 leaves at summit, 

 forming an involucre to the umbel. 



1. C. diandrus. 



1 Style 1-cleft. 



Brown Sedge. 



Culm slender, usually decumbent ; spikelets flat, oblong-lanceolate, acutish, 

 14 20-flowered, more or less in fascicles forming an umbel with 2 4 very short, 

 sometimes unequal rays; glumes oblong, obtusish, brown on the margin; 

 stamens 2. A little Sedge, distinguished by its reclining culm and brownish, 

 broad spikelets. It varies with glumes of a chestnut color, and also with 8 

 stamens. Stem 6' 1(X long. Leaves narrow-linear. Aug. Sep. 



2. C. Nuttallii. NuttaWs Sedge. 



Culms tufted, mostly erect ; leaves narrow-linear ; splkelets linear-lanceolate, 

 acute, flat, many-flowered, In crowded clusters, arranged in an umbel, with a 

 few mostly very short and nearly sessile rays ; glumes oblong-lanceolate, acute, 

 brownish. Stamens 2. A common, salt marsh species, especially distinguished 

 from the last by its narrower spikelets and leaves. Culm 4' 10' high. Aug 

 * * Style 8-clf/t. Achenia triangular. 



3. C. strigosus. Bulbous Sedge. 



Culm erect, leafy, tuberous at base; leaves broad-linear; umbel simple or 

 decompound ; spikclete narrow-linear, flat and flew-flowered, at length reflexed, 

 very numerous, in loose pedicellate clusters, on spikes forming an umbel, with 

 many long and unequal rays, which are sometimes branched; scales oblong- 

 lanceolate, yellowish ; stamens 8; achenium narrow-oblong. A very common 

 species in wet grounds, 1 2 ft high, distinguished by its numerous, narrow, 

 yellowish spikelets. Aug. 



4. C. dentatus. 



Toothed Sedge. 



Slender, erect, leafy at base ; leaves carinate, shorter than the stem ; umbel 

 composed of 4 6 branching rays ; spikelets ovate-lanceolate, flat, usually 6 10- 

 flowered, in pedunculate clusters of 36, forming a partial umbel on each ray ; 

 glumes very acute, brownish on the margin, green on the back; stamens 8; 

 achenium minute. A rather common species in wet, sandy soils, distinguished 

 by its completely compound umbel. Culm 8' 12' high. Aug. 



5. C. filic^lmis. Slender Sedge. 



Culm very slender, wiry, tuberous at base, mostly erect; leaves mostly 

 radical, very narrow-linear ; spikelets linear-lanceolate, with a somewhat con- 

 vex surface, 5 8-flowered, collected in a dense, globular, sessile head, which Is 

 either solitary or furnished with 1 2 smaller ones, on rather long, horizontal 

 rays; glumes ovate, loose, greenish ; stamens 3. A common species, 6' 12' 

 high, growing in dry soils, and distinguished by its globular heads of spikelets, 

 narrow leaves, and stem bulbous at base. Aug. 



6. C. inflexus. Dwarf Sedge. 



Culms low, very slender, tufted, leafy at base ; spikelets narrow-oblong, 8 

 10-flowered, collected in a few dense, ovoid heads, which are either sessile, 

 aggregated, or on short peduncles; involucre of 8 very long leaves; glumes 

 yellowish, oblong, tapering to a long, hooked point; stamen 1. A slendei 

 species, 2' 4' high, rather common in the sandy borders of ponds, distinguished 

 by its few, dense heads of spikelets, and its single stamen. Aug. Sep. 



2. DULlCHIUM. 

 Spikelete linear, compressed, arranged in 2 rows, on solitary, 



