400 
GRA MINE A E 
scopic lodicules force apart the paleae of the individual firs. Most 
sp. in Eur. are protogynous ; the sta. grow very rapidly in 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 fir. (p. 86). 
The fruit is a caryopsis (p. 108), i.e. an achene whose pericarp is 
completely 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 hilum 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 flowery endosperm. The embryo is straight, 
with its one cotyledon ( sciitellum ) completely enwrapping the radicle 
and plumule (this can be easily made out by dissecting soaked mate- 
rial). The radicle is towards the lower end of the fruit. In germination 
the cotyledon remains within the seed and extracts the nourishment 
from the endosperm; afterwards it merely withers away (p. 112). 
Most grass fruits are sufficiently light to be dispersed by wind, espe- 
cially as the paleae often remain attached to them and become dry 
and chaffy. Others have hooks or other adaptations for dispersal. Of 
special interest is the self-burying arrangement in Stipa (g.v.), effected 
by aid of the awn (this term is applied to any long thread-like out- 
growth of glume or palea). Many grasses, e.g. sp. of Poa and 
Festuca, are viviparous , especially on mountains. The spikelets are 
replaced by leafy shoots with adventitious roots at their bases. These 
drop off 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. (see p. 204), 
afford food to a large proportion of the earth’s inhabitants. Many 
grasses are valuable as fodder for domestic animals (see p. 203), or 
for hay. The bamboos supply many of the wants of the natives of 
trop. countries. 
Classification and chief genera (after Hack el) : the G. show near 
relationship only to Cyperaceae and perhaps Juncaceae, and are easily 
distinguished from these either by their vegetative or floral characters. 
A. Spikelets 1 -flowered without elongation of the axis beyond the 
flr., or 2-flowered with the lower flr. imperfect; without mea- 
surable internode between the individual glumes or paleae, 
and when ripe falling 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 laterally, but 
usually dorsally compressed or cylindrical. 
I. 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- 
