GROUP IV.— PHANEROGAMIA: ANGIOSPERM^ : MONOCOTYLEDONES. 545 



Sub-Class II.— GLUMIFLOR^. 



Flowers ambisporangiate or monosporangiafce and then mostly 

 monoecious, usually in heads or spikelets invested by imbricate 

 bracts : perianth absent, or scaly : ovary superior, uni- or multi- 

 locular, with one ovule in th^ loculus : seeds with endosperm. 



Cohort 1. Glumales. Ovary unilocular : ovule erect. 



Order 1. Graminace^. True Grasses. The leaves are alternate 

 on the stem, w^hich is known as the haulm ; the embryo lies on the 

 side of the endosperm (Figs. 346-7). The usually ambisporangiate 

 flowers generally have the formula KO, CO, -43 + 0, (rl ; they are 

 enclosed by bracts here termed palece, and are arranged in compli- 

 cated inflorescences ; the monomerous unilocular ovary contains 

 only one ovule ; the grain is the fruit, a caryopsis, to which one 

 (the inferior) or, less commonly, both, of the paleae sometimes 

 adhere, e.g. Barley and Oats. 



The flower is sessile in the 

 axil of a bract, which is 

 termed the inferior or outer 

 palea, sometimes also called 

 the flowering -glume (Fig. 355 

 hi, Z>2...), and there is also a 

 bracteole opposite to and 

 somewhat higher than this 

 which is termed the superior 

 or injier palea (Fig. 355 ps). 

 the flower. 



Within the inferior palea are usually two small (antero-lateral) 

 scales, the lodicules (sometimes only a single anterior one, 

 Melica), and occasionally (e.g. Stipa, some Bambusece Fig. 353 ^4), 

 there is a third scale situated posteriorly within the superior 

 palea. These lodicules are frequently regarded as rudimentary 

 perianth-leaves (Fig. 353), but it is more probable that they 

 are bracteoles, the two antero-lateral lodicules representing the 

 two halves of a single bracteole, present, as such, in Melica. 

 They grow and become succulent at the time of flowering, thus 

 forcing apart the paleae and the glumes (Fig. 354). Usually two 

 or more flowers, thus enclosed by palese, are present on an axis 

 (Fig. 355 x), and constitute the spikelet of the Grass, and beneath 

 the lowest flower there are usually two (or more) bracts which 



Fig. 353. — Diagrams of Grass- flowers. A 

 Bambusa. B Common type of Gramiuaceaj. 

 lu A there are three, in B two lodicules. 



The two paleoe completely enclose 



