yd 12. ALISMATACEAE 



1. Carpels on a large and distinctly convex receptacle. Inner perianth- 



segments petal-like, larger than, or almost as large as the outer. Stamens 



6 or more. [Tribe SAGITTARIEAE.] 3 



Carpels on a small and almost flat receptacle 4 



2. Flowers hermaphrodite. Ripe carpels numerous, slightly compressed, 



with many ribs. — Species 3. Central and North-west Africa. (Under 



Alisma L.l Echinodorus Engelm. 



Flowers unisexual or polygamous. Ripe carpels much compressed later- 

 ally 3 



3. Flowers monoecious or polygamous. Petals a little longer than the sepals. 



Carpels many. Ripe carpels with two crest-like ribs. — Species i. 

 Tropics. {Lophiocarpus Miq., under Sagittaria L.) 



Lophotocarpus Th. Dur. 



Flowers dioecious. Petals shorter than the sepals, white. Carpels 7 — 9. 

 Ripe carpels with 3 ribs. — Species i. German South-west Africa. 



Rautanenia Buchenau 



4. Petals much smaller than the sepals or wanting. Stamens 3 or 9. [Tribe 



WIESNEREAE.] 5 



Petals larger than the sepals, coloured. Stamens 6, rarely 9. [Tribe 

 ALISMEAE.l 6 



5. Flowers dioecious. Petals in the female flowers wanting. Stamens 9. 



Carpels about 12. — ■ Species i. East Africa. . . . Burnatia Mich. 



Flowers monoecious. Petals present, but very small and falling off early. 



Stamens 3. Carpels 3 — 6. — Species 2. East Africa and Madagascar. 



(Wisneria Mich.) Wiesnera Mich. 



6. Carpels 6 — 8, united at the base and spreading horizontally, containing 



2 or more ovules each and opening by a lid when ripe. • — Species 2. North 



Africa. The root -stock is edible Damasonium Tourn. 



Carpels 6 — 20, distinct, with a single ovule in each, indehiscent. . 7 



7. Flowers polygamous-monoecious. Carpels 15^ — 20. Pericarp bony within, 



hollow on either side. Leaves sagittate. — Species 3. Tropics. (Plate 

 6.) Limnophyton Miq. 



Flowers hermaphrodite. Leaves ovate, cordate, or lanceolate. . . 8 



8. Carpels 6 — 12, irregularly whorled, slightly compressed and 3 — 5-ribbed 



when ripe ; pericarp woody within. — Species 2. Tropics and Egypt. 



(Under Alisma L.) Caldesia Pari. 



Carpels 15—20, distinctly whorled, much compressed and 2-ribbed when 

 ripe ; pericarp leathery or parchment-like. — Species i. North and 

 East Africa. The root-stock contains starch and is used in medicine. 

 " Water-plantain." Alisma L. 



