Graminaceae i r 



Tribe 2. Hydrochariteae. Leaves floating. % flowers 

 stalked in the spathe. 



Leaves orbicular. Hydrocharis. 



b. Carpels usually 3. Placentae not projecting far 

 inwards. 



*Subfamily2. Vallisnerioideae. Fresh water plants. 

 Perianth often small. Stigma short. 



*Tribe. Hydrilleae. Leaves i -nerved, in whorls. ^ 

 flowers 1-3 in a spathe. 



Leaves linear, 3 in a whorl. *Elodea. 



7. Naked flowe7's do7ni?iant. Stamens rarely^ and carpels 

 never ^ indefinite. (For a see page 10, for ,8 see page 11.) 



Order 3. Glumiflorae. Grassy herbs with sheath- 

 ing leaves. Flowers naked, more rarely with perianth 

 of bristlesf, in the axils of imbricating bracts {ghiines). 

 Gynaecinm always i-locular with one ovule. 



Fam. I. Graminaceae. Herbs (grasses). Stems 

 usually terete. Leaves distichous, sheath usually split 

 to the base and furnished with ligule or hairs at junction 

 of sheath and lamina. Flowers in the axils of glumes 

 with 2-nerved ' palea' opposite glume, usually mon- 

 oecious, naked. The lowermost glumes are usually 

 without flowers {e^npty). Deeply bifid scale {lodiculae) 

 often present opposite palea. Stamens mostly 3. Anthers 

 versatile. Stigmas usually 2, feathery. Frnit a caryopsis J:. 

 Seed with copious endosperm. Embryo with peltate 

 enlargement {sciitelluni) of cotyledon in whose distal 



t Oreobohis^ a South American genus of Cyperaceae^ tribe 

 Rhync/wsporeae, has a perianth of glume-like tepals. 



X A caryopsis is a superior achene in which the pericarp and 

 testa are united. 



