ARACEAE.
FLOW. PL. AFR.
Pl. 12.
J. Fleischmann del.
Hydrosme grata Schott
A Leaf. B Inflorescence and spathe. C Stalk of the inflorescence. D Inflorescence without the spathe. E Stamen. F Stamen from above. G Pistil. H Pistil cut lengthwise. (B-H partly from a drawing in the Vienna Hofmuseum.)
1. Flowers hermaphrodite. 2
Flowers unisexual. 5
2. Perianth none. Ovary incompletely 2-celled with several ascending ovules. Climbing shrubs. Leaves stalked, lanceolate.—Species 2.
West Africa. Used as ornamental plants. (Raphidophora Schott).
[Tribe MONSTEREAE.] Afroraphidophora Engl.
Perianth of 4-6 segments. 3
3. Ovary 1-celled. Ovules 2 or more. Tall herbs. Juice milky. Root-stock tuberous. Leaves sagittate; stalk prickly.—Species 1. West
Africa. Used for making salt. [Tribe LASIEAE.] Cyrtosperma Griff.
Ovary 2-3-celled. Juice not milky. 4
4. Ovule one in each cell, ascending, inverted. Seeds exalbuminous. Climbing shrubs. Leaves stalked, lanceolate to ovate. Spathe oblong or ovate.—Species
1. Madagascar and Comoro Islands. [Tribe POTHOEAE.] Pothos L.
Ovules several in each cell, pendulous, straight. Seeds albuminous.
Herbs with a creeping root-stock. Leaves sessile, linear, sword-shaped.
Spathe linear, sword-shaped, forming a continuation of the flowering stem.—Species 1 (A. Calamus L., sweet-flag). Introduced in the
Mascarene Islands. Yields tanning-materials and is used in the preparation of perfumes, liquors, snuff, and medicaments. [Tribe ACOREAE.] Acorus L.
5. Perianth present. 6
Perianth none. 8
6. Perianth cupular. Ovary 1-4-celled with 2 or more ovules in each cell.
Juice milky. Leaves sagittate; stalk not thickened near the middle.
Spathe-margins connate below.—Species 20. Central and South-East
Africa. [Tribe STYLOCHITONEAE.] Stylochiton Leprieur
Perianth of 4 free segments. Ovary 2-celled with 1 ovule in each cell.
Juice not milky. Leaves pinnate; stalk with a thickened joint near the middle. Spathe-margins free. [Tribe ZAMIOCULCASEAE.] 7
7. Stamens with free filaments; anthers opening by slits. Leaves several, once pinnate. Spathe upon a short stalk.—Species 1. East Africa and Mascarene Islands. Used as an ornamental plant. Zamioculcas L.
Stamens with united filaments; anthers opening by pores. Leaf 1, thrice pinnate in the adult stage. Spathe upon a long stalk.—Species 2.
East Africa to the upper Congo. Gonatopus Hook. fil.
8. Stamens united throughout their length or almost so. 9
Stamens free or united in pairs or at the base only. 17
9. Female (inferior) part of the spadix adnate to the spathe, 1-flowered.
Stamens 2. Floating water-plants. Juice not milky.—Species 1.
Tropical and South Africa and Egypt. Used medicinally. [Tribe
PISTIEAE.] Pistia L.
Female part of the spadix free from the spathe, several-flowered.
Stamens 3-8, very rarely 2. Land- or marsh-plants. Juice milky. 10
10. Stem creeping. Leaves lanceolate, parallel-veined, with numerous primary and secondary lateral veins. Ovary completely or incompletely
2-3-celled with numerous ovules.—Species 12. West Africa. [Tribe
ANUBIADEAE.] Anubias Schott
Stem erect or tuberous. Leaves ovate, ovate-sagittate or dissected, net-veined, rarely parallel-veined with 5 primary lateral nerves. 11
11. Ovules 1-3. Spadix with barren flowers below and above the male ones.
Stem short, ascending. Leaves ovate or sagittate, entire, with about
5 primary lateral nerves and many parallel secondary ones.—Species
2. Madagascar and neighbouring islands and Zanzibar. They yield fibre and edible tubers and seeds and are used in medicine. Typhonodorum Schott
Ovules 4 or more. Leaves sagittate- or cordate-ovate and net-veined, or dissected. 12
12. Ovules 4. Female flowers with staminodes. Spadix with a terminal appendage. Stem tuberous. Leaves dissected.—Species 1. Seychelles.
[Tribe PROTAREAE.] Protarum Engl.
Ovules more than 4. Leaves sagittate- or cordate-ovate. [Tribe COLOCASIEAE.] 13
13. Ovary completely 1-celled. Ovules straight or almost so. 14
Ovules incompletely 2-3-celled. Ovules inverted. Spadix without a terminal appendage. 16
14. Ovules few, basal. Stem erect. Spadix with a terminal appendage.—Species
1. Cultivated and sometimes naturalised in Madagascar and the neighbouring islands. Stem and leaves are edible; also used as an ornamental plant. Alocasia Schott
Ovules many, parietal. Stem tuberous. 15
15. Spadix with a terminal appendage. Spathe erect. Stamens 3-6.—Species
1 (C. antiquorum Schott, taro or dinde). Cultivated and sometimes naturalised in Tropical and North Africa. The tubers and leaves are eaten and used in medicine; also an ornamental plant. (Under Caladium
Vent.) Colocasia Schott
Spadix without an appendage. Spathes recurved at the top. Stamens
2-3.—Species 1. Island of Socotra. Used as an ornamental plant. Remusatia Schott
16. Style disc-like, adnate to the styles of the neighbouring flowers. Ovules with a long funicle. Leaves leathery.—Species 2. Cultivated and sometimes naturalised in West Africa and the Mascarene Islands. Used as ornamental plants or vegetables. Xanthosoma Schott
Style none. Ovules with a short funicle. Leaves herbaceous, usually with red spots.—Species 1. Cultivated and sometimes naturalised in West Africa. Used as an ornamental plant. Caladium Vent.
17. (8.) Stem above ground and usually climbing or underground and creeping.
Spadix without an appendage. Ovary 1-2-celled with 1 ovule in each cell. 18
Stem underground, short and thick, more or less tuberous. Juice milky. 23
18. Juice milky. Leaves cordate or sagittate. Female inflorescence not adnate to the spathe. Ovary 1-celled. [Tribe NEPHTHYTIDEAE.] 19
Juice not milky. Leaves lanceolate oblong or elliptical, acute or obtuse at the base, rarely cordate and then female inflorescence adnate to the spathe or ovary 2-celled. Seed albuminous. 22
19. Stem underground, creeping.—Species 3. West Africa. Used as ornamental plants. (Including Oligogynium Engl.) Nephthytis Schott
Stem above ground, climbing, woody. 20
20. Leaves perforated or dissected. Male inflorescence three times as long as the female and contiguous to it. Ovary with a strongly projecting parietal placenta.—Species 2. West Africa. Rhektophyllum N. E. Brown
Leaves entire or lobed, not perforated. Ovary with a slightly projecting parietal or sub-basal placenta. 21
21. Leaves oblong, shortly cordate at the base. Male inflorescence twice as long as the female and contiguous to it. Stamens 2-3.—Species 1.
West Africa (Cameroons). (Under Cercestis Schott). Alocasiophyllum Engl.
Leaves sagittate or hastate. Stamens usually 4.—Species 7. West
Africa. Cercestis Schott
22. Stem creeping. Female inflorescence adnate to the spathe, as long as the male. Ovary conical. Style present.—Species 1. Central Africa.
Used as an ornamental plant. [Tribe CALLOPSIDEAE.] Callopsis Engl.
Stem climbing or erect. Female inflorescence free from the spathe.
Ovary subglobose. Style wanting.—Species 17. Central Africa. Some are used as ornamental plants. [Tribe CULCASIEAE.] Culcasia Beauv.
23. (17.) Spadix covered with fertile flowers to the top. Ovary with 4 or more ovules. Leaves sagittate or hastate. Spathe funnel-shaped.—Species
10. South Africa and southern Central Africa; one species
(Z. aethiopica Spreng.) cultivated as an ornamental plant under the name of “Calla” and naturalised in the island of Madeira. (Aroides Heist.,
Richardia Kunth). [Tribe ZANTEDESCHIEAE.] Zantedeschia Spreng.
Spadix ending in an appendage which is glabrous or covered with rudimentary flowers, rarely without an appendage, but then ovary 1-2-ovuled and leaves dissected. 24
24. Ovules inverted. Ovary usually 2-4-celled. Male and female portions of the spadix contiguous, rarely separated by a glabrous interval without barren flowers. Leaf 1, dissected. [Tribe AMORPHOPHALLEAE.] 25
Ovules straight. Ovary 1-celled. Seeds albuminous. Spadix with a terminal appendage. [Tribe AREAE.] 27
25. Spadix ending in a flowerless appendage.—Species 35. Tropics. Some have edible tubers or are used as ornamental plants. (Under Amorphophallus
Blume). (Plate 12.) Hydrosme Schott.
Spadix covered with flowers to the top; upper flowers sometimes reduced
to barren stamens. 26
26. Ovary 1-celled. Male inflorescence as long as the female. Spathe boat-shaped.—Species
7. Central Africa. Some have edible tubers. Anchomanes Schott
Ovary 2-celled. Male inflorescence longer than the female.—Species 2.
Equatorial West Africa. (Including Zyganthera N.E. Brown). Pseudohydrosme Engl.
27. Spadix unisexual (containing male or female flowers only). Stamens 2-4.
Ovules basal. Leaves dissected.—Species 4. East Africa. Some are poisonous. Arisaema Mart.
Spadix bisexual (containing both male and female flowers). 28
28. Male inflorescence contiguous to the female. 29
Male inflorescence separated from the female by a distinct interval usually covered with rudimentary flowers. 30
29. Stamen 1. Anther opening by a slit. Ovules basal. Leaves sagittate or hastate.—Species 2. North Africa. Used as ornamental plants.
The tubers are poisonous when raw, but edible when cooked, and furnish starch, medicaments, and a substitute for soap. Arisarum Targ. Tozz.
Stamens 3-4. Anthers opening by pores. Ovules basal or apical. Leaves several dissected.—Species 2. North-west Africa. Used as ornamental plants. The tubers are poisonous when raw, but edible when cooked, and furnish starch, medicaments, and a substitute for soap. Dracunculus Schott
30. Interval between the male and the female inflorescence without rudimentary flowers. Spathe divided into two chambers, one of which contains a female flower, the other one several male flowers. Stamens 2. Ovules numerous. Leaves ovate.—Species 1. North-west Africa (Algeria). Ambrosinia Bassi
Interval between the male and the female inflorescence clothed with rudimentary flowers. Spathe not 2-chambered. Female flowers several. 31
31. Ovules 6 or more, parietal. Stamens 3-4. Leaves sagittate or hastate.—Species
2. North Africa. Poisonous and sometimes used as ornamental plants. The tubers are edible when cooked and yield starch; they are also used in medicine and as a substitute for soap. Arum L.
Ovules 1-4, basal. Stamens 1-2. Leaves linear, oblong, ovate, or dissected. 32
32. Ovule 1. Leaves several, entire.—Species 3. North Africa. Used as ornamental plants. The tubers are edible when cooked, and yield starch, medicaments, and a substitute for soap. Biarum Schott
Ovules 2-4. Leaf 1, dissected.—Species 2. East Africa and Angola.
Used as ornamental plants. The tubers are edible when cooked, and yield starch, medicaments, and a substitute for soap. Sauromatum Schott
[FAMILY 20.] LEMNACEAE