2 MONOCOTYLEDONEAE 



6. Perianth wanting or rudimentary, that is, reduced to small, hypogjTious, free 



or partially-united scales, rarely {Potamogetonaceae) replaced by sepaloid 



appendages of the connective 7 



Perianth well developed, calyx- or corolla-hke or consisting of calyx and 

 corolla, rarely {Eriocaulaceae and Restionaceae) wanting in the female 

 flowers 15 



7. Flowers in the axils of membranous or more or less dry bracts (glumes) in 



spikelets consisting of one or several flowers and one or several empty 

 glumes and nearly always arranged in spikes, racemes, panicles, or heads. 

 Land-, marsh-, or freshwater-plants. Carpel solitary, with a single basal 



or laterally attached ovule 8 



Flowers in spadices with a fleshy rachis and surrounded by one or several 

 spathes, more rarely sohtary or in glomerules, heads, or spikes ; in the 

 latter case [Potamogetonaceae) saltwater plants 9 



8. Embryo enclosed in the lower part of the albumen. Seed and ovule attached 



at the base, free from the pericarp and the wall of the ova^3^ Style i, 

 with I — 3 stigmas. Anthers usually affixed at the base. Sheaths of 

 the cauline and inner radical leaves closed all round, usually without a 

 ligule. Stem usually triangular solid and without nodes. 



17. Cyperaceae. 

 Embryo outside the albumen, at its base. Seed and ovule attached laterally, 

 but often near the base, usually adnate to the pericarp or the wall of the 

 ovary. Style i, with i — 6 stigmas, or styles 2. Anthers usually affixed 

 at the back. Sheaths of the leaves nearly alwaj^s split on one side and 

 ending in a ligule. Stem usually cyhndrical and hollow between the nodes. 



16. Gramineae. 



9. Plants without differentiation into stem and leaves, consisting of small 



floating leaf- or granule-hke shoots. Flowers 2 — 3 together in cavities 



of the shoots 20. Lemnaceae. 



Plants differentiated into stem and leaves 10 



10. Flowers solitary or in glomerules in the axils of the leaves. Carpel solitary. 



Naias, 9. Naiadaceae. 



Flowers in spikes, spadices, or heads, rarely [Potamogetonaceae) solitary or 



in glomerules, but then several separate carpels ii 



11. Male flowers in panicles, female in heads or spadices. Flowers dioecious. 



Leaves narrow, usually serrate or prickly. Stem usually woody. 



Pandanus, 6. Pandanaceae. 

 Male or all flowers solitary or in spikes, heads, or cymes 12 



12. Flowers in globose heads Sparganium, 7. Sparganiaceae. 



Flowers solitary or in spikes, spadices, or cymes. 13 



13. Ovaries several, separate, rarely ovary solitary, and then marine plants, 



very rarely freshwater-plants with hermaphrodite flowers. If flowers 

 in spadices or spikes, then hermaphrodite or polygamous with i or several 



one-ovuled ovaries 8, Potamogetonaceae. 



Ovary solitary. Land-, marsh-, or freshwater-plants; the latter with uni- 



