CYPERACEAE 



49 



Pontederia — Pickerel-weed 

 (Nam d foi Pontedera, an Italian botanist) 

 \ ecies growing in ed| nds; Aoweri bine, conspicuous /'. a rdata 



Poales Grass Order 



Cyperaceae — Sedge Family 

 iss-like herbs, annual or perennial ; stems mostly solid and triangular, roots fibrous, !■ 

 mostly long and narrow, with closed sheaths, 3 -ranked on the stem; flowers in short spikes i spik--- 

 each flower in the axil of .1 scale (glume, bract), without a calyx or corolla, bul sometimes with 

 barbed bristles or hairs, scales 2 ranked or spirally arranged, stamens I 3, filaments slender, anthers 

 attached at the base; pistil with Z-3-cleft style, ovary I -celled, seed 1, free; fruit a lens 

 triangular nutlet or achene. 



Key to the Genera 



1. Flowers perfect, spikes (spikelets) all of one sort 



a. Spikes cone-shaped; scales very numerous and spirally imbricated 



(1) Achene crowned by a cap or tub.- HeleochartS 



(2) Achenes without a cap or tubercle Scirpus 



b. S] tikelets) flattened; scales 2-ranked 



(1) Flowers without bristles, achenes beakless Cyperus 



(2) Flowers with 6-10 bristles, achenes beaked Dulichium 



2. Flowers monoecious, in the same or in separate spikes, or sometimes 



dioecious; achene enclosed in a sack Carcx 



I [eleocharis — Spike Rush 



(Gr. helos, marsh, chairo, delight in, referring to its home) 



1. Plants tufted, without conspicuous rootstocks //. ovita 



2. Plants not tufted, perennial from an elongated rootstock //. pahislris 



Scirpus — Bulrush. Club Rush 



(I.at. scirpus, bulrush) 



1. Tall aqnatic rush, inflorescence without leafy involucre S. validus 



2. Swamp or wood plants, involucre leafy 



Style 3-cleft, achene 3-angled, bristles 6 S. atrozircns 



b. Style 2-cleft, achene plano-convex, bristles 4 5. microcdrpus 



rv 



1 !ypei us diandrua 

 (luster and spikelet 



- rpua validus 

 (luster and spikelet 



