GRASSES 75 
the parallel veins of the leaf (a character common to most 
Monocotyledons) and the well-marked mid-rib ; also that 
the leaves are broad, thick, and juicy. Look carefully at 
the spot where the sheath and the blade meet, and note 
the thin scale-like outgrowth named the ligule. A ligule 
is very generally present in the leaves of grasses, and it 
always has the same form in each distinct kind or species. 
Its form should always be carefully noted, as grasses that 
are very much alike when out of flower can often be 
clearly distinguished by the ligule. Sometimes the ligule 
is wanting or absent, and sometimes, as in the native 
species of Danthonia, it has the form of an incomplete 
ring of hairs. Note how the leaves are arranged on the 
‘culm ; a leaf on one side is followed by a younger leaf on 
the opposite side. The leaves are said to be alternate on 
the stem. Pull the top of a green culm out of the leaf 
sheath. Notice its pale colour and that it is juicy and 
fragile. The sheath protects and supports the tender 
lower part of the internode—the part where growth in 
length is going on. Chew the lower end of the internode 
pulled out of its sheath and note its sweet taste. It 
contains a little sugar. Some grasses, such as the Sugar- 
cane and Black Millet (Sorghwm) contain a great deal of 
sugar. 
Find a full-grown culm with the flower-bearing branches 
at the top. Note that the flowers grow in very small 
flattened clusters called spikelets. The spikelets are 
crowded together into thick oval masses and are all turned 
to one side. Each spikelet contains three flowers (some- 
times more, sometimes fewer). The parts of a spikelet can 
be better seen in the Oat or in Wheat. Note here the two 
chaffy scales or glumes placed outside the flowers and 
protecting them, and later on protecting the “seed ” also 
‘These glumes are called “empty glumes.” 
