The flowering plants of Africa / An analytical key to the genera of African phanerograms - Franz Thonner

SUBORDER NYMPHAEINEAE

Aquatic herbs. Leaves floating, undivided, usually peltate. Flowers solitary. Sepals 3 or more. Petals 3 or more. Stamens numerous. Anthers opening inwards by longitudinal slits. Carpels 6 or more, distinct or united below into a many-celled ovary. Stigmas free or partly united. Fruit indehiscent or bursting irregularly. Seeds albuminous.—Genera 3, species 20.

1. Carpels separate, few-ovuled. Sepals 3. Petals 3. Flowers red, axillary.
Leaves ovate, without stipules.—Species 1. Southern West Africa
(Angola). Used medicinally. (Hydropeltis Michx.) [Subfamily CABOMBOIDEAE.] Brasenia Schreb.
Carpels united, at least on the outside, many-ovuled. Sepals 4-5. Petals numerous. [Subfamily NYMPHAEOIDEAE.] 2
2. Sepals 4. Ovary more or less free from the calyx, but adnate to the corolla and the stamens. Seeds with an aril. Leaves with a stipule.
Leaf- and flower-stalks with 4-7 large air-canals.—Species 20. Used as ornamental and fodder-plants; the root-stock and the seeds are edible and yield a drink, medicaments, and a dye. “Water-lily.”
(Castalia Salisb.) [Tribe TETRASEPALEAE.] Nymphaea Smith
Sepals 5. Petals smaller. Flowers yellow. Ovary free. Seeds without an aril. Leaves without stipules. Leaf- and flower-stalks with many small air-canals.—Species 1. North-west Africa (Algeria). Used as ornamental plants, as fodder, and for the preparation of a drink. (Nymphaea
Salisb.) [Tribe NUPHAREAE.] Nuphar Smith

[FAMILY 77.] CERATOPHYLLACEAE

Branched submerged aquatic herbs. Leaves whorled, deeply divided into forked, linear segments. Flowers solitary or in pairs in the axils of the leaves, without bracteoles, unisexual. Perianth simple; segments 9-12, subequal, united at the base, greenish or whitish. Stamens 12-16, inserted upon a convex receptacle; anthers opening outwards. Ovary superior, 1-celled. Ovule 1, pendulous, straight. Style simple; stigma entire, grooved. Fruit a nut. Seed with a thin albumen; embryo with a large, many-leaved plumule.

Genus 1, species 3. Ceratophyllum L.

SUBORDER RANUNCULINEAE

[FAMILY 78.] RANUNCULACEAE

Herbs, undershrubs, or shrubs. Leaves usually divided. Perianth simple or consisting of a calyx and a corolla of free petals, hypogynous or nearly so. Stamens usually numerous. Anthers opening by longitudinal slits. Carpels superior, solitary or separate, rarely (Nigella) united. Ovules inverted. Seeds with a straight embryo and copious albumen.—Genera 11, species 140. (Plate 46.)