320 
AROIDEjE. 
Suborder III. LEMNEvE. 
Perianth 0. Fl. 2, monoecious, in a membranous spath. 
5. Lemna. Spath 2-flowered, membranous, urceolate. Male 
fl. of 2 stamens. Fr. utricular, intlehiscent. — Fronds with- 
out distinct stem or leaves. Fl. from just beneath the mar- 
gin of the frond. 
Suborder I. Typhineee. 
1. Typha Linn. 
1. T. laiifolia (L.) ; 1. linear nearly flat, sterile and fertile cat- 
kins contiguous. — E. B. 1455. — St. 6 — 7 feet high. L. over- 
topping the inflorescence, very broad. Catkins very long. — 
Ponds and lakes. P. VI. Great Reed-mace. 
2. T. angustifolia (L.) ; 1. linear channeled below, sterile and 
fertile catkins a little separated from each other. — E. B. 1456. — 
St. 5 — 6 feet high, much slenderer than in the preceding. L. 
very narrow, overtopping the inflorescence. Catkins very long, 
slender, separated by an interval of about an inch. — Lakes and 
ponds. P. VI. VII. Lesser Reed-mace. 
[3. T. minor (Sm.) ; 1. linear-setaceous, sterile and fertile 
catkins distant, the latter at length elliptical. — E. B. 1457. — 
Reported to have been found on Hounslow Heath. Dillenius. 
P. VII.] E. 
2. Sparganium Linn. 
1. S. ramosum (Huds.) ; 1. triangular at the base with concave 
sides, st. branched, stigma linear. — E. B. 744. — About 2 feet 
high. L. long. Fl. in spherical heads. — Ditches. P. VII. 
Branched Bur-reed. 
2. S. simplex (Huds) ; 1. triangular at the base with flat sides, 
st. simple, stigma linear. — E. B. 745. — About 1 foot high. St. 
not branched but the lower heads of fl. are stalked. — Ditches. 
P. VII. Simple Bur-reed. 
3. S. nafans (L.) ; 1. floating flat, st. simple, stigma oblong. — 
E.B. 273. — St. often very long, floating. L. very long, pellucid. 
Heads of fl. few, barren head usually solitary.— Lakes and 
ditches. P. VII. VIII. 
Suborder II. Arinece. 
3. Acorus Linn. 
1. A. Calamus (L.) ; scape with a long leafy prolongation be- 
yond the spadix. — E. B. 356. — St. 5 — 6 feet high, resembling 
the 1., ensiform, flattened. Spadix completely covered by the 
