290 
LEMNACEAE. 
1.—LEMNA. 
Key to species. 
Fronds } inchlong — ... e. 0 l. minor. 
Fronds } inch long es ze --. 2. polyrrhiza. 
l. L. minor, Linn. ; Hook. f. Fl. Brit. Ind. vi. 556. Common in 
pools, Hongkong ; ; Hongkong New Territory without 
locality ; Ngchungshan, near Hongkong. Fl. —— 
2. L. polyrrhiza, Linn. ; Hook. f. l. c. 557. In swamps at East 
Point, Hongkong; LN gchungshan, near Hongkong. Fl.——. 
ALISMACEAE. 
Key to genera. 
l. Leaves cordate .. 2. Met pus 
Leaves not cordate 
2. Leaves lanceolate dens d "on 
Leaves linear, hastate o or r sagittate es) | 9. Sagittaria. 
1.—ALISMA. 
. A. Plantago, Linn.; Hook. f. Fl. Brit. Ind. vi. 559. Lienchow 
River. FI. pink, August. 
a 
HG BORISOOR ARE UN 
. Hongk. 346. ' Beleher's B and Sheko, 
Reni ng ; Hoitung ; Shiukwan (Shaochaufu) N. River. 
Fl. white, September. 
3.—SAGITTARIA. 
1. S. sagittifolia, Zinn.; Hook. f. Fl. Brit. Ind. vi. 561. 
okfulam, Hongkong ; Chaochaufu ; Hoifung ; Canton ; 
Macao; Sanning; North Ri iver. Fl. white, A pril — August. 
NAIADACEAE. 
Key to genera. 
l. Flowers rite aa oat a 2. 
Flowers bisexual a = sa 3. 
2. Stamens 6 or more — ... es) «ee L Aponogeton. 
Stamens (anthers) 4. ... aS -. 2. Potamogeton. 
3. eque (anthers) 9. , 3. Ruppia. 
1 
ae xs Su 4, 
4. Filament dede mor ee e. 4, Zannichellia. 
Anthers sessile .. p i 5. j 
