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

ORDER RHAMNALES

Shrubs or trees, rarely (Helinus) undershrubs. Leaves undivided, stipulate, more rarely (Phylica) exstipulate. Flowers regular, hermaphrodite or polygamous. Receptacle more or less cup-shaped. Sepals 4-5, valvate in bud. Petals 4-5 or 0. Stamens as many as and alternate with the sepals. Anthers opening by 1-2 slits. Disc within the stamens, sometimes indistinct. Ovary 2-4-celled, sometimes not quite completely septate, rarely (Maesopsis) 1-celled. Ovules solitary in each cell, basal, inverted. Style undivided or cleft. Seeds with a large, straight embryo.—Genera 18, species 140. (Plate 88.)

1. Ovary superior or almost so. 2
Ovary inferior or half-inferior. 9
2. Ovary 1-celled. Stigma 5-lobed. Fruit one-seeded, indehiscent. Leaves opposite or nearly so, penninerved.—Species 2. Equatorial regions.
The fruits are edible. (Including Karlea Pierre) Maesopsis Engl.
Ovary completely or almost completely 2-4-celled. Stigma 2-4-lobed, or 2-4 stigmas. 3
3. Anthers opening outwards. Sepals with a far projecting ledge on the inside. Disc ring-shaped. Style undivided, with a 2-lobed stigma.
Leaves opposite or nearly so, crenate, with 2-4 lateral nerves on each side. Flowers in axillary spikes or in terminal panicles.—Species 1.
Abyssinia. Lamellisepalum Engl.
Anthers dehiscing inwards or laterally. Flowers solitary or in cymes, rarely in racemes or panicles, but then style 2-4-cleft or with 3 stigmas. 4
4. Leaves 3-, more rarely 5-nerved from the base. Style 2-4-cleft. Fruit wingless, fleshy, indehiscent, with a 1-4-celled stone.—Species 10.
Some of them yield timber, tanning and dyeing materials, gum-lac,
food for silk-worms, medicaments, and edible fruits (jujubes) from which
a sort of bread and a beverage are prepared; others have poisonous fruits; some are used as hedge plants. Zizyphus Juss.
Leaves penninerved. 5
5. Flowers in terminal panicles, 5-merous. Stigmas 3. Fruit with 3 stones.
Shrubs with spiny branches. Leaves opposite.—Species 1. Northern
East Africa. The fruits are edible. Sageretia Brongn.
Flowers in axillary inflorescences. 6
6. Receptacle united with the fruit for the greatest part. Fruit with 2-4 indehiscent stones. Seeds not grooved. Disc thick. Spines in the axils of the leaves.—Species 3. Tropical and South Africa. (Adolia
Lam.) Scutia Brongn.
Receptacle free from the fruit for the greatest part. Disc thin, rarely thick, but then spines, as usually, wanting. 7
7 Fruit with 1 two-celled stone. Disc thick. Style 2-cleft. Flowers 5-merous.
Leaves alternate.—Species 1. East Africa. The fruits are edible. Berchemia Neck.
Fruit with 2-4 stones. Disc thin. 8
8. Fruit with a red skin and a woody stone separating into 3 elastically dehiscing portions. Seed-coat crustaceous, shining. Flowers 5-merous.
Leaves alternate.—Species 1. Madagascar. Macrorhamnus Baill.
Fruit with 2-4 leathery or thin-woody, scarcely or not dehiscing stones.
Seed-coat thin.—Species 17. North, East, and South Africa. They yield timber, dyes, a substitute for hop, fish-poison, and medicaments.
“Buckthorn.” Rhamnus L.
9. (1.) Ovary half-inferior. 10
Ovary inferior. 15
10. Style simple; stigma 3-lobed. Leaves penninerved, serrate or crenate. 11
Style 2-4-cleft. 12
11. Ovary incompletely 2-3-celled, 1-2-ovuled. Fruit drupaceous, 1-celled,
1-2-seeded. Trees. Leaves opposite or nearly so. Flowers in axillary, raceme-like cymes. (See 2.) Maesopsis Engl.
Ovary completely 3-celled, 3-ovuled. Fruit separating into 3 dehiscing mericarps, 3-seeded. Shrubs. Leaves alternate. Flowers in axillary and terminal cymes or panicles.—Species 1. South Africa and St.
Helena. Noltia Reichb.
12. Leaves 3-5-nerved from the base, alternate. Fruit a drupe. Stem erect or decumbent. 13
Leaves penninerved. Fruit a nut, a schizocarp, or a capsule. 14
13. Fruit with a horizontal wing; epicarp leathery, endocarp woody. Leaves
3-nerved, serrate; stipules transformed into spines. Flowers in axillary and terminal, raceme-like cymes.—Species 1. Cultivated and naturalized in Algeria. Used medicinally and as a hedge-plant. Paliurus Juss.
Fruit not winged; epicarp fleshy, endocarp horny, woody or leathery.
(See 4.) Zizyphus Juss.
14. Ovary 2-celled. Style 2-cleft. Fruit with a long wing-like appendage, dry, 1-seeded, indehiscent. Climbing shrubs. Leaves alternate.—Species
3. Madagascar and neighbouring islands, West Africa. They yield fibres, tanning and dyeing materials, and medicaments. (Plate 88.) Ventilago Gaertn.
Ovary 3-celled. Style 3-cleft or 3-parted. Fruit not winged, 3-seeded.
Erect or almost erect, hairy shrubs or trees. Leaves opposite. Flowers in lateral inflorescences.—Species 6. Tropics. Lasiodiscus Hook. fil.
15. (9.) Style simple, sometimes very short, with 1-3 stigmas. Fruit separating into 3 dehiscing mericarps. Seed-coat hard. Hairy plants. Leaves alternate, entire, nearly always exstipulate. Flowers solitary or in spikes, racemes, or heads.—Species 80. South Africa, southern
Central Africa, Madagascar and the neighbouring islands. Some are used as ornamental plants. Phylica L.
Style 2-4-cleft. Leaves stipulate. Flowers in cymes sometimes arranged in false spikes or racemes, very rarely flowers solitary. 16
16. Receptacle top-shaped, not prolonged beyond the ovary. Fruit separating into 3 elastically dehiscent mericarps. Erect shrubs or low trees.
Leaves alternate, 3-nerved at the base, serrate. Flowers in axillary cymes.—Species 1. East and South-east Africa, including the islands. Colubrina Brongn.
Receptacle prolonged beyond the ovary. 17
17. Stem tree-like. Leaves opposite, entire, penninerved, hairy beneath.
Flowers in axillary cymes. Anthers dehiscing by longitudinal slits which are confluent at the apex. Fruit separating into dehiscent mericarps; epicarp somewhat fleshy.—Species 1. Island of St.
Helena. Nesiota Hook. fil.
Stem shrubby, half-shrubby, or climbing. Leaves alternate. Flowers in axillary and terminal inflorescences. 18
18. Stem not climbing, without tendrils. Leaves few, lanceolate, entire.
Flowers solitary or in few-flowered cymes.—Species 1. South Africa
(Betchuanaland). Marlothia Engl.
Stem climbing, bearing tendrils. Leaves oval. Flowers in usually many-flowered cymes, false spikes, or panicles. Mericarps 3, separating from
a central column. 19
19. Flowers in cymes. Disc entire. Fruit wingless; mericarps dehiscing elastically. Leaves entire, penninerved.—Species 3. Tropical and
South Africa. Helinus E. Mey.
Flowers in false spikes or racemes. Disc usually lobed. Fruit 3-winged; mericarps dehiscing by a narrow slit or indehiscent—Species 12.
Tropics. Some are used medicinally. Gouania L.

[FAMILY 138.] VITACEAE.

Shrubs or trees, usually climbing, rarely (Cissus) herbs or undershrubs. Leaves alternate, stipulate. Flowers regular, in cymose inflorescences. Calyx small, entire or lobed. Petals 3-7, sometimes cohering at the base or at the apex, valvate in bud. Stamens as many as and opposite to the petals, inserted outside the hypogynous, sometimes indistinct disc. Anthers opening inwards by two longitudinal slits. Ovary 2-8-celled, seated upon the disc or more or less sunk in it. Ovules solitary in each cell or two side by side, ascending, inverted, with ventral raphe. Style simple, sometimes indistinct. Stigma entire or 2-4-lobed. Fruit a berry, usually septate. Seeds with a bony or crustaceous testa and a fleshy or cartilaginous, more or less ruminate albumen enclosing a small straight embryo.—Genera 5, species 200. (AMPELIDEAE.) (Plate 89.)

1. Filaments united with one another and with the petals. Ovary 3-8-celled, with 1 ovule in each cell. Erect shrubs or trees, without tendrils.
Leaves 1-3 times pinnate.—Species 3. Tropics. They yield vegetables, edible fruits, dyes, and medicaments, and serve as ornamental plants. [Subfamily LEEOIDEAE.] Leea L.
Filaments free from each other and from the petals. Ovary 2-celled, with
2 ovules in each cell. [Subfamily VITOIDEAE.] 2
2. Flowers polygamous-dioecious. Petals 5, cohering at the top and falling off together. Disc 5-lobed. Style very short, conical. Seeds pear-shaped, with two pits on the ventral face. Climbing shrubs. Leaves more or less distinctly 3-5-lobed. Inflorescences paniculate, often with tendrils.—Species 1 (V. vinifera L., grape-vine). North Africa, also cultivated in other regions. It yields edible fruits, also used for preparing wine vinegar and brandy, oily seeds, and medicaments. Vitis Tourn.
Flowers hermaphrodite or polygamous-monoecious. Petals usually spreading at the time of flowering, very rarely cohering at the top, but then only 4. Seeds more or less egg-shaped. 3
3. Style short-conical or wanting. Petals usually 5. Disc ring-shaped.
Seeds egg- or boat-shaped. Climbing shrubs. Inflorescences with tendrils.—Species 30. Tropics. Some have edible fruits. (Under
Cissus L. or Vitis Tourn.) Ampelocissus Planch.
Style filiform or columnar, usually rather long. Inflorescences mostly without tendrils. 4
4. Petals 5 or 6, very rarely 4 or 7, thickened, fleshy, persistent. Disc adnate to the ovary. Style usually short. Climbing shrubs. Inflorescences compact.—Species 15. Central and South Africa. (Under Cissus L. or Vitis Tourn.) Rhoicissus Planch.
5. Petals 4, not thickened. Disc usually saucer-shaped, 4-lobed and adnate to the ovary at the base only. Style usually long.—Species 150.
Tropical and South Africa and Egypt. Some of them yield edible fruits or tubers, mucilage, or medicaments. (Under Vitis Tourn.) (Plate 89.) Cissus L.

VITACEAE.

FLOW. PL. AFR.