27 (24^) Grasses, sedges or rushes; leaves narrow and sheathing the stem. To deter- 

 mine grasses, sedges, and rushes read the following key characters and deter- 

 mine to which of the three groups your plant belongs. These are difficult groups 

 to identify and only the dominant species found along the marine fringe are in- 

 cluded. If doubtful, consult some reference such as Gray's Mamial of Botany 

 (Fernald, 1950) or Gleason and Cronquist (1963): 



A (27) Grasses (Gramineae). Stems cylindric, hollow except at the nodes (a few 

 have soft pith); leaves in two ranks on the stem, parallel veined; leaves 

 in two parts, a sheath enveloping the stem but open its full length and a 

 flat blade; at junction of sheath and the blade a membranous or hairy 

 appendage, the ligule (see Plate I), this will be the principal character 

 illustrated to designate the species; fruit a grain 85 



B (27) Sedges (Cyperaceae). Stems usually solid and many are triangular (three 

 angled) ; roots fibrous; leaves in three ranks, when present, sheath closed 

 at the top; infloresence, a spike or cluster at top of the stem, flowers lack 

 petals and sepals, one flower in axile of each imbricated bract (scale) 

 which is usually brown; fruit an achene 86 



C (27) Rushes (Juncaceae). Stems pithy or hollow, unbranched; leaves nar- 

 rowly lanceolate or filiform, in basal clumps (tussocks), or represented 

 by sheaths only; cymose or clustered small greenish or brownish flowers; 

 fruit a capsule 87 



27 (2i) Plants not grasses, sedges or rushes, leaves usually broader 28 



28 (27) Plants extremely succulent (water in tissues) and fleshy, in some cases only 

 the leaves of this type; leaves then are very thick and firm between the fin- 

 gers; plants of exposed areas of beaches, dunes, and tidal marshes (if in doubt, 

 try this choice) 29 



28 (27) Plants not extremely succulent or fleshy; leaves not thick and firm between the 

 fingers; plants more varied in their habitat, but usually not in extremely ex- 

 posed areas 39 



29 (28) Plants with cylindrical (terete) leaves that look like extensions of the stem 30 



29 (28) Plants with broader leaves, not cylindrical, or leaves reduced to scales 31 



15 



