746 THE SUBDIVISIONS OF THE VEGETABLE KINGDOM. 



undivided, linear, parallel-veined lamina (vol. i. fig. 150'), and a sheathing basal 

 portion. At the junction of blade and sheath is inserted a little scale — the ligule. 

 Flowers hermaphrodite and unisexual, arranged in spikelets (c/. fig. 231, p. 139). 

 Pei'ianth absent, its place being taken in many cases by 2 tiny -scales, the lodi- 

 cxdes, sometimes regarded as reduced perianth-leaves. Each flower is inclosed in a 

 sheathing scale known as a palea, whilst outside this and subtending the flower is a 

 bract-like structure, the fiowering glume; this is often awned. Every flower is thus 

 inclosed in a palea and flowering glume, whilst the whole spikelet is inclosed in a 

 little 2-leaved involucre consisting of 2 outer glumes, The ovary bears 2 feathery 

 stigmas, and contains a single ovule. The stamens are generally 3 in number, 

 though variations are met with. The pollen is dust-like. Pollination has been 

 fully described on pp. 140-142. The fruit or grain is indehiscent, and is known 

 as a caryopsis. The seed contains a floury endosperm, and an embryo placed at 

 one side (c/. vol. i. figs. 141 ^- *• *, p. 599). The intemodes of the haulm are in Zea, 

 Andropogon, Panicum, &c., filled with pith; in the majority of Gi-asses they are 

 hollowed. The Bamboos and numerous other tropical Grasses have upright 

 perennial stems, and form an arborescent vegetation (cf. vol. i. p. 713). Bamboos 

 attain a height of 25 metres and a diameter of nearly half a metre. But the 

 majority of Grasses produce new haulms each year from their subterranean 

 rhizomes, and these die down at the end of the season. The female flowers of the 

 Maize {Zea Mais) are borne on thick spadices (cobs) inclosed in sheathing bracts. 

 Grasses are widely distributed over the globe, the tropics being richer in species 

 than the temperate regions, but poorer in individuals. Grasses are found extending 

 into arctic and alpine regions to the extreme limits of phanerogamic vegetation; 

 thus in the Alps Poa laxa has been found at an elevation of 3000 metres. The 

 Bamboos are tropical and sub-tropical; in the Steppes certain Grasses are very pre- 

 dominant, e.g. the genera Stipa and Feshica (cf. Plate VI. vol. i. p. 616). In moist, 

 temperate climates. Grasses form a continuous carpet, the basis of meadow land. In 

 marshy places and by river banks reed-like Grasses occur in great quantities (e.g. 

 Phragmites cominunis). 



Gramineae number about 3500 species. 



Cyperacece. — Annual and perennial plants with upright, haulm-like stems, 

 jointed below and with long upmost segment. The leaves much resemble those of 

 GraminesB, but the ligule is wanting. Flowers hermaphrodite and unisexual, aggre- 

 gated into spikelets, inclosed in bract-like scales. Perianth absent, or represented 

 by scales, bristles, or hairs. The ovary is 2- or 3-carpellary. Stamens in one or 

 two whorls of 3 each; pollen dust-like, pollination by wind. The seed contains 

 endosperm. In the Scirpese the leaf-blades are frequently obsolete, and assimila- 

 tion is carried on by the stems. Scirpus lacustris reaches a height of 1, Papyncs 

 antiquorwm (or Cyperus Papyrus, fig. 424) of 3 metres and a diameter of 10 centi- 

 metres. The pith of the larger flowering stems of this plant cut into thin strips, 

 united together by narrowly overlapping margins, and then crossed under pressure 

 by a similar arrangement of strips at right angles, constituted the papj^rus of 



