[Illustration: FIG. 288.--_Bromus mollis_: _A_ inflorescence; _B_ the uppermost flower of a spikelet, with its axis turned forward; in front is seen the two-keeled inner pale (bracteole) and the stamens protrude between this and the outer pale (bract); _C_ an ovary with the 2 stigmas on its anterior side, the 2 lodicules, and the 3 stamens; _D_ the fruit seen from the dorsal side; _E_ the same from the ventral side.] [Illustration: FIG. 289.--Diagrammatic outline of a spikelet: _n Y_ lower glume; _ø Y_ upper glume; _n I_ upper pale; _ø I_ the inner pale; _l_-_l_ lodicules; _st_ stamens; _I_-_I_ main axes; _II_ lateral axes.] [Illustration: FIG. 290.--Diagram of the Grass-flower: _ni_ outer pale; _øi_ inner pale; _l_-_l_ lodicules.] [Illustration: FIG. 291.--Longitudinal section of an Oat-grain: _a_ the skin (pericarp and testa); _b_ the endosperm; _c_ the cotyledon; _d_ the plumule.] Only a few Grasses have a _solid stem_, such as Maize, Sugar-cane, and _Andropogon_. The _blade_ is flat in the meadow-grasses, but the Grasses which live on dry places (“prairie-grass”) exposed to the sun, often have the blade tightly rolled up and almost filiform or bristle-like, with anomalous anatomical structure. A _closed_ tubular _sheath_ is found in _Melica uniflora_, _Bromus_-species, _Poa pratensis_ and _trivialis_, _Briza_ and some _Glyceria_-species. The sheath is developed for the purpose of supporting the young internodes while their growth is proceeding at the base. The “nodes” (the swollen joints which are seen on stems of Grasses) are not really part of the stem but are formed by the base of the leaf-sheath. They play a part in assisting the haulms to regain a vertical position when laid prostrate by wind or rain. The _awn_ on the pale is homologous with the blade of the Grass-leaf, and the pale itself is the sheath. The arrangement of the leaves in the _spikelet_ is similar to that in _Cyperus_ and other Cyperaceæ, their floral-leaves being borne in several rows in _Streptochæta_. More than two barren “glumes” are found in _Streptochæta_, several Phalarideæ and others. The spikelets, too, are again arranged in two rows in the axils of suppressed floral-leaves. The inflorescence becomes a “compound spike” (ear) when the spikelets are sessile. In the majority of instances the spikelets are borne on long stalks; when these branch, then the secondary branches, and similarly all branches of higher order, are placed so far down upon the mother-axis that they all appear to be of equal value and to arise in a semicircle from the mother-axis itself, though in reality they arise from each other (_Panicle_, Fig. 288 _A_). Sometimes the main axis and branches of different orders unite together as in _Alopecurus_, _Phleum_, and some other Grasses, and hence the single (short-stalked) spikelets appear to arise