MONOCOTYLEDONS. 
1 (a) Ovary superior or naked, 2. 
(b) Ovary inferior. 34. 
2 (a) Perianth-leaves sepaloid or wanting. 8. 
(b) Perianth-leaves petaloid, or the inner 
petaloid, the outer sepaloid.* Leaves 
undivided. 19. 
3 (a) Minute aquatic plants, showing no dis- 
tinction into stem and leaves, but merely 
consisting of a disc-like or almost glob- 
ular thallus, which sometimes gives off 
shoots of a similar shape, roots, and 1-3 
flowers. Stamen 1. Ovary 1-celled. 
Lemnaceae. 
(b) Plants with a stem and leaves; both or 
either distinctly evoluted. 4, 
4 (a) Leaves plaited in the bud, afterwards 
more or less deeply divided. 5. 
* Compare Palmae, the perianth-leaves of which are 
sometimes nearly petaloid, or separated in sepals and 
petals by shape and connection, but equal in colour and 
texture. They have pinnately or palmately divided 
leaves. 
