CLASS TEIANDRIA. 
13.^ 
on account of the shape of their leaves, 
which are long, narrow, and pointed. 
Fig. 130 represents the Ixia (black- 
berry lily) ; <^ is an entire flower ; h the 
corolla cut lengthwise, showing the three 
stamens. At c is the flower of the mat- 
grass {N'a/rdus)^ having but one pistil, and 
therefore separated from the grass family, 
the greater part of which we shall meet 
with in the next order of this class. 
173. Order Digynia^ two pistils. — "We 
find here the natural family of the grasses 
{GrraminaGe(B)\ they are distinguished by 
a straight^ holloiv^ and jointed stem, or culm / the long and 
linear leaves are placed at each joint of the stalk, in alternate 
order, inclosing it like a sheath ; flowers in spihelets formed 
of an outer envelope of one or two bracts, called glumes^ and 
an inner envelope (corolla) of two bracts, called palece^ which 
constitute the chaff of oats, rye, &c. 
a. These little flowers are best observed in a mature stage of the plant when, then 
bracts being expanded, three filaments appear, containing each a large double 
anther ; the two pistils have a reflexed, feathered stigma. They have no seed- 
Yessel ; each seed is contained within the bracts, which gradually open, and unless 
the seed is gathered in season it falls to the ground. This facility for the distribu- 
tion of the seed is one cause of the very general diffusion of grasses. The roots of 
grasses are fibrous, and increase in proportion as the leaves are trodden down, or 
consumed ; and the stalks which support the flower are seldom eaten by cattle, so 
that the seeds are suffered to ripen. Some grasses which grow on very high 
mountains, where the heat is not sufficient to ripen the seed, are propagated by 
suckers, or shoots, which rise from the root, spread along the ground, and then take 
root ; such grasses are called stoloniferous. Others are propagated in a manner 
not less wonderful ; for the seeds begin to grow while in the flower itself, and 
new plants are there formed, with little leaves and roots ; they then fall to the 
ground, where they take root. Such grasses are called viviparous, which signifies 
producing their offspring alive, either by bulbs instead of seeds, or by seeds 
germinating on the plant. The seeds of the grasses have but one lobe, or are 
not naturally divided into parts like the apple-seed and the bean ; therefore these 
are said to be monocotyledonoxLS. The stems of gramineous plants, like those of all 
the monocotyledons, are endogenous. With regard to the duration of the grass- 
like plants, some are annual ; as wheat, rye, and oats, whose roots die after the 
grain or seed is matured. The meadow grasses are perennial ; their herbage dying 
in autumn, and the roots sending out new leaves in the spring. 
174. The family of grasses is one of the most natural of all the vegetable tribes: 
the plants which compose it seem at the first glance to be so similar that it would 
appear impossible to separate them into species, much less into genera ; but scien- 
tific research presents us with differences sufficient to form a basis for the estab- 
lishment of a great number of genera. These genera are chiefly distinguished by 
the different form of the corollas and the shape of the leaves. The essential charac- 
ter of the oat consists in the jointed, twisted awn or beard, which grows from the 
back of the blossom ; the oat is also remarkable for its graceful panicle. The rye 
173. Describe the grass family — a. Filaments — Pistils — Roots of grasses— Manner in which grasses 
are propagated — Seeds — How do the stems of the grasses grow ? — Duration of grass-like plaKts.— 
174. What is remarked of the separation of the grassey into genera and species I — Uow are the go&eni 
dibtinguished 3 
Fig. 130. 
