iced otie 
é oh ell lat staan cee le Om einai de ine i ara aed Beech tee Ral be doe 
ee! oe ee 
45 
4 
4 
Ut 
Ga) Leaves linear re 
/4 3a.Leaves basal 
i. Herbs 1-2 m, tall; leaves sirordlike Typha (p.— 
‘o Herbs rarely as mch as 90 cm, tall, usually 
2-4 much less 
18 4Aa,Leaves mostly 5-30 mm, long 
7,9 Plants submerged in usually l-2 feet of water 
along shelving sand lake shores, a () 
Ki é forming flowers, the leaves abruptly 
\ expanded and membranous at the base Isoetes (p.- 
£9 Plants not as described 
£.0Flowers in globose heads Spargenium =. 
. , Flowers in racemes Triglochin (p a 
[3 4b. Leaves 3-5 om, long 
‘> Leaves acute, tapering Subularia ( _— 
“+. Leaves expanded towards the tips Limosella (p.- 
/4 3b. Leaves distributed along the stems 
, Ja. Leaves opposite or whorled 
i: Leaves in whorls of 6-9 or more Hippuris ‘p-- 
'@ Leaves in whorls of 3 (see 3rd categ.) Elodea 
; + Leaves opposite 
’: Leaves provided with minute spines along the 
-. marging as viewed with a lens Naias ip: a 
_~ Leaves entire 
.. Leaves commonly 2-5 cm, long Zennichellia ‘i - 
Ce. Leaves commonly .5-2 cm, long Callitriche | 
+b Leaves prevailingly alternate 
j)< Very fragile herbs of shallow water with 
threadlike stems and leaves; flowers axillary Howellia p 
Commonly coarse herbs, rarely with flattened 
linear leaves; flowers in spikes Potamogeton 
f - 
= am 
