130 



ORDER CXLI. EQUISKTACE^. 



the next, usually -with a membranous Hgule bet^veen the base of 

 the leaf and sheath. Flowers in spikes, racemes or panicles, 

 usually perfect, in 1-niany-flowered spikelets, composed of glume- 



Fig. 42. 



Fig. 4T. 



like bracts in 2 rows. Outer bracts {glumes), 2, rarely 1, often 

 unequal ; the inner 2 immediately inelosmg each flower (palecB), 

 alternate. Perianth none, or consisting of very small, membran- 

 ous scales {squamulae). Stamens 1 — 6, commonly 3. An- 

 thers versatile. Ovary 1-celled. Styles 2. Stigmas 2, 

 feathery. Fruit a caryopsis. 



A very large and most important order, diffased through all parts of 



the world ia the greatest abundance. The herbage furnishes food for 



cattle and other herbivorous animals, while their seeds, known as the 



Fig. 43. Cereal Grains, form the most important article of human sustenance. 



None are poisonous, except a single species, the Darnel Grass {Lolvwm). 



The poisonous properties of Ergot are caused by a parasitic fungas. The stems 



of many of the species afford sugar, which is most abundant in the different 



species of Sugar-Cane {Saccha- 

 rum), and is found also in the 

 Indian Corn {Zea). Among the 

 grains, the most important are 

 the Oat {A'cena\ ng. 41, the 

 Wheat, Eye, Eice, Barley, and 

 Maize. The most valuable kinds 

 for grazing purposes are Agros- 

 tls (Eed-top), Phleum (Timothy 

 Herds-grass), and other mea- 

 dow and pasture Grasses 'com- 

 prising especially various species 

 of Poa and Festuca. In fig. 42 

 is represented Erngrostis megas- 

 tachya, illustrating one of the 

 most common forms of Grasses. 

 In fig. 43 we have a many- 

 flowered, awnless spikelet of a 

 Glyceria ; and in fig. 44, a many- 

 flowered spikelet of Bromns, 

 with awned paleco. Panicum la- 

 tlfoHnm, fig. 45, is a representative of another tribe, whose peculiar structure is 

 well illustrated in the spikelet of Panicum Crus-Galli, fig. 46, where we have 

 two flowers, one of which only is complete, the other being reduced merely to 



Fig. 44. 



Fig. 46. 



a pair of paleae, so that each spikelet has four palese, two of which are, in this 

 case, awned. In fig. 47 is represented Elymus Virginicus, a native example of 

 the tribe to which the "Wheat, Eye, and Barley beloug. 



Fig; 45. 



SEMES II.— CEYPTOGAMIA. 



Plants ■without proper flowers, eontaining stamens and pistils, 

 not reproduced by proper seeds eontaining an embryo, but by 

 spores or reproductive cells. 



CLASS III.— ACROGENS. 



Plants with a regular axis of growth, distinguished more or 

 less into root and stem, and usually into leaves also ; their struc- 

 ture made up of woody and cellular tissues, and the various ves- 

 sels found in higher plants ; the axis increasing in height and not 

 in diameter, and aU growth taking place at the terminal bud oJ 

 the stem or branch. 



Okdeb CXLI. — Equisetacese. 



Leafless plants, with jointed, grooved stems, either simple, oi 

 with vertieillate branches, which are hollow and closed at the 

 joints, each terminating in a dentate sheath. Inflorescence a 

 dense, cyUndrio, terminal spike, or strobile, composed of peltate, 

 hexagonal scales ; each scale with several thecae or spore-cases 

 attached to its under surface, opening longitudinally. Spores 

 numerous, with 4 elastic threads, called elaters, wrapped round 

 them. 



An order consisting of a single genus, Eqnisetum (Scourinff Jiush, Fipes_ 

 Rorsetail), found in damp grounds in all parts of the world. 



