GRAMINEAE 301 



warm weather and suspend the anthers clear of the paleae so that the 

 loose powdery pollen is easily blown away and may be caught by the 

 large stigma of another fl. 



The fruit is a caryopsis, i.e. an achene whose pericarp is com- 

 pletely united to the seed-coat. Its construction can be well seen 

 in maize (or wheat) ; at the broad end is the scar of the style, and on 

 the under side at the pointed end is the embryo; on the upper side is 

 the hilnm or point where the ovule was attached to the wall of the 

 cpl. (the form of this scar is important in classification) ; the bulk 

 of the seed consists of floury endosp. The embryo is straight, with 

 its one cot. {scufellitm} completely enwrapping the radicle and plumule 

 (this can be easily made out by dissecting soaked material). The 

 radicle is towards the lower end of the fr. In germin. the cot. 

 remains within the seed and extracts nourishment from the endo- 

 sperm ; afterwards it withers away. Most grass frs. are sufficiently 

 light to be dispersed by wind, esp. as the paleae often remain 

 attached to them and become dry and chaffy. Others have hooks. 

 Self-burying arrangement in Stipa (g.v.), effected by aid of the awn 

 (this term is applied to any long thread-like outgrowth of glume or 

 palea). Many grasses, e.g. sp. of Poa and Festuca, are viviparous, 

 esp. on mountains. The spikelets are replaced by leafy shoots with 

 adv. roots at their bases. These drop oft" and grow upon the soil 

 (cf. Agave, Allium, &c.). 



From the economic point of view the G. are only rivalled in 

 importance, if at all, by the Palmae and Leguminosae. The cereal 

 grasses, e.g. Oryza, Triticum, Zea, Avena, Hordeum, &c. afford food 

 to a large proportion of the earth's inhabitants (see Edible Products). 

 Many grasses are valuable as fodder (q.v.} for domestic animals, or 

 for hay. The bamboos (q.v ) supply many of the wants of the natives 

 of trop. countries, Japan, &c. Many are used as sandbinders, &c. 



Classification and chief genera (after Hacke!) : the G. show near 

 relationship only to Cyperaceae and perhaps Juncaceae, and are easily 

 distinguished from these either by their veg. or floral characters. 

 A. Spikelets i-flowered without elongation of the axis beyond the 

 fl., or 2-flowered with the lower fl. imperfect; without 

 measurable internode between the individual glumes or 

 paleae, and when ripe fatting off from the stalk as a whole 

 or together with certain parts of the axis of the spike, 

 a. Hilum point-like; spikelets not compressed lat., but 

 usually dorsally compressed or cylindrical. 



1. Maydeae (inf. palea and, when present, sup. palea thin and 



membranous ; glumes firm, even leathery or cartilaginous, 

 the lowest one the largest and overlapping the rest ; spike- 

 lets usu. in racemes or spikes which become jointed when 

 ripe; $ and spikelets in separate infls. or in separate 

 parts of the same infl.); Euchlaena, Zea, Coix. 



2. Andropogoneae (as I, but spikelets 5, or i and ? side by side 



in the same infl.): Saccharum, Andropogon, Sorghum. 



3. Zoysieac (paleae membranous; glumes herbaceous, papery 



or leathery, the lowest usu. the largest ; spikelets falling 

 singly or in groups from an unjointed spike-axis) : Zoysia. 



