GRAMINEAE. 6 1 



cells, each 2-parted. Fruit a many-seeded berry. [Greek, referring to the aquatic 

 habitat.] Three or four species, natives of America. 



i. Limnobium Spongia (Bosc.) L. C. Richard. FROG'S-BIT. (I. F. f. 209.) 

 Blades of the leaves orbicular or broadly ovate, cordate or reniform, faintly 5-7- 

 nerved and cross-veined, purplish and spongy beneath, 2-5 cm. broad, on petioles 

 225 cm. in length. Stolons rooting and sending up flowers and leaves at the 

 nodes; peduncles of the staminate flowers, 7-10 cm. long, those of the pistillate 

 flowers stouter, 2.5-5 cm. long, nodding in fruit. In shallow, stagnant water, Lake 

 Ont. to Fla., 111., Mo. and La. July-Aug. 



Order 3. GRAMINALES. 



Grasses and sedges. Monocotyledonous plants, mostly herbaceous, 

 with leafy or leafless, usually simple, stems (culms), the leaves usually nar- 

 row and elongated, entire or minutely serrulate. Flowers mostly perfect, 

 small, incomplete, in the axils of dry, chaffy scales (glumes) arranged in 

 spikes or spikelets. 



Fruit a caryopsis (grain); culm mostly hollow. Fam. i. Gramineae. 



Fruit an achene ; culm solid. Fam. 2. Cyperaceae. 



Family i. GRAMINEAE Juss.* 

 Grass Family. 



Annual or perennial herbs, of various habit, rarely shrubs or trees 

 Culms (stems) generally hollow, but occasionally solid, the nodes closed 

 Leaves sheathing, the sheaths usually split to the base on the side oppo- 

 site the blade ; a scarious or cartilaginous ring, naked or hairy, rarely 

 wanting, called the ligule, is borne at the orifice of the sheath. Inflo- 

 rescence spicate, racemose or paniculate, consisting of spikelets composed 

 of two to many 2-ranked imbricated bracts, called scales (glumes), the 

 two lowest in the complete spikelet always empty, one or both of these 

 sometimes wanting. One or more of the upper scales, except sometimes 

 the terminal ones, contains in the axil a flower, which is usually enclosed 

 by a bract-like awnless organ called the palet, placed opposite the scale 

 and with its back toward the axis (rachilla) of the spikelet, generally 2- 

 keeled ; sometimes the palet is present without the flower, and vice versa. 

 Flowers perfect or staminate, sometimes monoecious or dioecious, sub- 

 tended by 1-3 minute hyaline scales called the lodicules. Stamens 

 1-6, usually 3. Anthers 2-celled, versatile. Ovary i-celled, i-ovuled. 

 Styles 1-3, commonly 2 and lateral. Stigmas hairy or plumose. Fruit 

 a seed-like grain (caryopsis). Endosperm starchy. About 3500 species 

 widely distributed throughout the world, growing in water and on all 

 kinds of soil. Those yielding food-grains are called cereals. The 

 species are more numerous in tropical countries, while the number of 

 individuals is much greater in temperate regions, often forming extended 

 areas of turf. The time of year noted is that of ripening seed. 



KEY TO THE TRIBES AND GENERA. 



A. Spikelets i or 2-flowered, when 2-flowered the upper fertile, lower staminate; 

 rachilla articulated below the scales or the subtending involucre, and not extending 

 beyond the flowers. 

 Spikelets not flattened laterally. 



Flowering scale and palet hyaline ; none of the scales spiny. 



Spikelets monoecious ; staminate and pistillate in the same panicle. 



I. Maydeae. 



Spikelets in pairs, perfect, or the pedicellate one staminate, empty, rudimentary 

 or wanting. II. Andropogoneae* 



* Contributed by Mr. GEO. V. NASH. 



