590 GBAMINE^E. (GRASS FAMILY.) 



included in the sheaths of the upper leaves, the upper one stamiuate and ex- 

 serted. Glumes 2, hyaline, the lower one emarginate, the upper acute. Palet 

 none. Stamens 6. Styles 2 : stigmas elongated. Grain ovoid, free. 



1. H. Carolinensis, Beauv. (Zizania fluitans, Michx.) Floating in 

 still water or creeping on muddy banks, Florida to North Carolina. Jnly- 

 August. Culm filiform, branching, 4 - 2 long. Leaves 1' -2' long. 



15. ZIZANIA, Gronov. WILD RICE. 



Rank water grasses, with broad flat leaves, and large diffuse panicles of 

 moncEcious 1 -flowered spikelets, on club-shaped jointed pedicels. Glumes 2, 

 membranaceous, the lower one of the pistillate spikelets awned. Stamens 6. 

 Stigmas elongated, brush-shaped. Grain cylindrical, free. 



1. Z. aquatica, L. Spikelets of the lower portion of the panicle stami- 

 nate, of the upper pistillate ; awn straight, elongated ; styles 2 ; grain linear. 

 Deep marshes and ponds, common. July. Culms 4 - 8 high. Leaves 

 rough beneath. Panicle l-2 long. 



2. Z. miliacea, Michx. Panicle diffuse ; staminate and pistillate spike- 

 lets intermixed ; awns short; styles united, elongated ; leaves smooth, with 

 rough margins; grain oval.- With the preceding. April - May. Culms 

 4 - 6 high. Leaves somewhat glaucous. 



16. PHARUS, P. Browne. 



Aquatic grasses, with broad flat leaves, petiole-like sheaths, and monoecious 

 flowers disposed in a simple terminal panicle. Spikelets by pairs, unequal, 

 the smaller pedicelled, hexandrous, the larger pistillate, with the flowering 

 glume indurated, involute. Empty glumes 2, thiu. Style long; stigmas 3. 

 Grain linear, included. 



1. P. latifolia, L. Floating; leaves oblong, rough beneath, longer than 

 the sheath ; flowering glume pointed, downy on the back, twice as long as the 

 lanceolate empty glumes. Orange Lake, Florida (Herb. Thurber). 



17. ROTTBCELLIA, L. f. 



Erect perennial rrtostly tall grasses, with flat or channelled leaves, and spiked 

 inflorescence. Spikes nearly terete, jointed. Spikelets awnlcss, in pairs at 

 the base of each joint ; one imperfect, on a coriaceous and closely appressed 

 pedicel: the other perfect, sessile, embedded in an excavation of the joint, 2- 

 flowered. Glumes 4, the exterior flat, coriaceous, with a hingp-like depression 

 at the base, the interior boat-shaped, membranaceous. Palets hyaline. Sta- 

 mens 3. Styles 2. Grain compressed, free. Spikes solitary on lateral and 

 terminal peduncles or branches. 



1 . R. mgosa, Nutt. Culms compressed ; peduncles or branches in pairs, 

 short, included in the sheaths of the upper leaves ; spikes spreading, slightlv 

 compressed ; lower glume lanceolate, transversely rugose ; sterile flower neu- 

 tral. Pine barren swamps and ponds, Florida to North Carolina. Sept. 

 Culms 2 -4 high. Spikes green, If -2' long, 1" in diameter. 



