GKOUP IV. PHANEROGAM1A : ANGIOSPERMJ! : MONOCOTYLEDON ES. 547 



position of the branches of the panicle is more or less bilateral ; 

 dorsiventral, when (e.g. Festuca) the branchlets of the main 

 branches of the panicle all arise on the same side (unilateral or 

 secund panicle). 



The andrcecinm consists commonly of one (Fig. 353 B) or two 

 (A) whorls of 2-3 stamens ; when there is but one whorl of 

 stamens, it corresponds to the outer whorl in those flowers in 

 which two whorls are present. Sometimes (e.g. LuzioJa, Ochlandra, 

 Pariana) the stamens are numerous (about 1820), or there may 

 be but one or two. When there are normally only two stamens, 

 they are usually situated in the median plane (e.g. Anthoxanthum), 

 sometimes in the lateral plane (e.g. Coleanthus); but where this 

 is the result of suppression (Diarrhena, Orthoclada) they are 

 postero- lateral, the anterior stamen being suppressed : when there 

 is only a single stamen, this is generally the anterior stamen (e.g. 

 species of Festuca and Andropogon), the two postero-lateral 

 stamens being suppressed. 



The monomerous gyn88ceum consists of a single median carpel 

 (Fig. 353), bearing 13 styles (see p. 524): the single, somewhat 

 campylptropous ovule is sessile on the ventral suture of the carpel. 



The stem is generally characterised by swollen or tumid nodes, 

 to which the sheathing leaf-bases contribute. The long interned es 

 are hollow : the sheathing leaf-bases are largely developed, and 

 frequently extend over several internodes. A membranous ligule 

 is developed at the junction of leaf-base and lamina (see p. 48; 

 Fig. 28). 



The more common Grasses are classified as follows : 



Series A. PANICOIDE^E : spikelet one-flowered, or sometimes two-flowered 

 and then the lower flower is imperfect ; articulated so that it falls off entire 

 after flowering ; no prolongation of the axis beyond the flower. 



Tribe 1. Panicece: spikelets dorsally compressed, in compound spikes: 

 glumes 3, of which the lowest is the smallest : inferior palea without an awn. 



Panicum glabrnm (Digitaria humifusa), P. (Echinuchloa) Crus-galli, and P. 

 (Setaria) viride occur occasionally on cultivated land. P. miliaceum yields 

 Millet (Fig. 354). 



Tribe 2. Maydece : the diclinous flowers are in distinct ppikelets ; the two 

 kinds of spikelets usually form distinct inflorescences, but sometimes they occur 

 in different parts of the same inflorescence : the lowest glume is the largest. 



Zca Mais, the Maize Plant, cultivated in warm countries, is a native of 

 Tropical America : the $ spikelets form a loose panicle at the apex of the 

 haulm, and the 9 flowers are borne laterally on a thick spadix, which is en- 

 sheathed by leaves. Coix belongs to this tribe. 



