70 
THE AMERICAN BOTANIST. 
when it is remembered that all the cereals, such as oats, 
barley, rye, wheat, rice and corn, are grasses as well as 
sugar cane, sorghum, broom corn, millet, timothy and the 
many forage species. Only one genus (LolHum) is known 
to contain poisonous species. 
Although grasses as a rule have stems that are solid 
only at the joints, there are some exceptions to this as in 
Indian corn and sugar cane where the stems are solid 
throughout. The leaves are in two ranks and usually 
clearly divided into a sheath enclosing the base of the long 
intern ode and a narrow blade extending out from it. At 
the juncture of blade and sheath there is usually a scale- 
like out-growth parallel with the internode called the 
ligule. This is a very characteristic feature of grasses. 
The sheath is generally split down to the base on the side 
opposite the blade but occasionally it is entire and tubular. 
In the flow^ers may be detected a general resemblance 
to the ordinary three-parted flower of the monocotyledons 
but some of the parts are reduced or w^anting and this 
coupled with the presence of various chaffy scales and 
bracts make trouble for those who would identify the 
plants. The plan of the flow^er may be better understood 
if it is known that the spikelets of grass flowers are com- 
parable to a raceme with its bracts. The empty scales, 
called glumes, at the base ol the spikelets are in the nature 
of true bracts and the chaff-like scale called a palet imme- 
diately subtending the flower represents a bracteole. 
There is a perianth usually of two small members called 
lodicules, and occasionally a third member is present 
making the three-parted perianth. Within these are 
usually found three stamens though in the bamboos there 
are six. The pistil is a single carpel which ripens but one 
seed. This seed, closely invested hj the ovary wall forms 
the fruit known as a caryopsis. Occasionally the ovary 
wall becomes succulent, forming a drupe-like fruit. In the 
genus Melocanna according to Rendle, it reaches a length 
of several inches and is edible. In some of the bamboos 
the walls of the ovary become hardened and nut-like. 
