Araceae (Arum lily family)

Life > eukaryotes > Archaeoplastida > Chloroplastida > Charophyta > Streptophytina > Plantae (land plants) > Tracheophyta (vascular plants) > Euphyllophyta > Lignophyta (woody plants) > Spermatophyta (seed plants) > Angiospermae (flowering plants) > Monocotyledons > Order: Alismatales

About 106 genera and about 4025 species, native mainly to the tropics and subtropics, but also with some species in temperate regions; especially diverse in New World tropics. Nine genera and 31 species are native to southern Africa, one genus and one species is naturalised, and a further 18 genera and 40 species are cultivated in the region. The Lemnaceae has been synonymised with the Araceae and previous members of this family are included here. They are all aquatic plants with small floating leaves and tiny flowers.

Genera native to southern Africa

Information from Singh (2000), Plants of Southern Africa - an Online Checklist (SANBI), Flora of Zimbabwe and Flora of Mozambique.

Amorphophallus About 150 species, found throughout the Old World tropics, with three species native to southern Africa and a further species that is cultivated in the region. The genus includes Amorphophallus titanum (Titan arum) from Sumatra, which holds the record as the plant with the largest unbranched inflorescence in the World, with a record height of 2.94 m (see Wikipedia).
Gonatopus Five species, found in tropical and southern subtropical Africa, with four species native to southern Africa, occuring in the northeastern regions.
Stylochaeton About 15 species, native to tropical and southern subtropical Africa, with three species native to southern Africa.
Zamioculcas The only species is Zamioculcas zamiifolia (Fern arum), which has a native distribution that includes Kenya, Tanzania, Malawi, Zimbabwe, Mozambique and South Africa (KwaZulu-Natal). See Flora of Zimbabwe.
Zantedeschia Eight species, all of which are native to southern Africa.

Genera previously included in the Lemnaceae

Information from Glen (2000), Plants of Southern Africa - an Online Checklist (SANBI) and Flora of Zimbabwe

Lemna Thirteen species worldwide of which three are native to southern Africa.
Spirodela Two of the three species are native to southern Africa.
Wolffia Three species native to southern Africa.
Wolffiella Nine species worldwide, with four species native to southern Africa.

Genera naturalised in southern Africa

Information from Singh (2000) and Plants of Southern Africa - an Online Checklist (SANBI)

Pistia

One species, the Water Lettuce Pistia stratiotes, found worldwide in warm regions, and a naturalised weed in southern Africa. It is a declared Category 1 invasive plant in South Africa.

Other genera, cultivated in southern Africa

List from Glen (2002). Acorus was previously placed in the Araceae but now is placed in its own order (Acorales) and family (Acoraceae).

Aglaonema About 20 species, native to the tropical forests of Asia. Grown particularly as pot plants. Two species are cultivated in southern Africa: Aglaonema commutatum and Aglaonema crispum (latter native to the Philippines)
Alocasia About 70 species, found in tropical forests and damp, shady places in S and SE Asia. Five species are cultivated in southern Africa.
Anthurium About 700-900 species found in wet mountain forests of tropical and subtropical North and South America. Five species are cultivated in southern Africa.
Arisaema About 150 species, from moist woodland and rocky wasteland in Asia and North America. Two species cultivated: Arisaema dracontium and Arisaema triphyllum, both of which are native to eastern Canada and the USA.
Arisarum vulgare (Friar's cowl) Native from the Mediterranean to the Azores.
Arum About 26 species, distributed in S Europe, N Africa and W Asia to the W Himalayas. Two species are cultivated in southern Africa: Arum italicum (Italian lords-and-ladies) (native from the Canary Islands to Cyprus) and Arum palaestinum (native to Israel). Other species in the Araceae are referred to by their common names as arums, e.g. Zantedeschia aethiopica.
Caladium bicolor Native to northern South America.
Colocasia esculenta (Taro, Cocoyam, or in Zulu 'Amadumbe') Native to tropical eastern Asia. Grown as a staple food, including in southern Africa, where it was probably introduced by Portuguese traders before 1500.
Dieffenbachia seguine (Dumb cane) Native to tropical America.
Dracunculus vulgaris (Dragon Arum) Native from Corsica to Turkey.
Epipremnum pinnatum (Money plant) Native from Malaysia to New Guinea.
Monstera deliciosa (Delicious Monster) The Delicious Monster is widely cultivated in gardens and is so called because the ripe fruit can be eaten. Eating the unripe fruit is not recommended because it contains calcium oxalate crystals.
Montrichardia linifera Native to northern South America.
Philodendron About 500 species, native to the Americas, mainly in rain forest. Eight species are cultivated in southern Africa.
Sauromatum venosum (Voodoo lily) Native to the Old World tropics, from West Africa to Burma. Inflorescences have a foetid smell.
Spathiphyllum A total of 36 species, native to tropical regions of Indonesia, the Philippines and the Americas. Often grown as indoor plants. Three species are cultivated in southern Africa.
Syngonium About 33 species, native to Central and South America. Two species are cultivated in southern Africa: Syngonium macrophylla (native from Mexico to Ecuador) and Syngonium podophyllum (native from Mexico to Bolivia).
Typhonium blumei Native to China and Japan.

Characteristics (excluding genera previously in Lemnaceae)

Flowers

The following characteristics distinguish members of the Araceae from other families:

they have an inflorescence termed a spadix consisting of small closely packed flowers arranged round a swollen, fleshy column.
the spadix has a (usually) large, petal-like bract wrapped round its base termed a spathe.

Some species have separate male and female (i.e. unisexual) flowers (e.g. Arum Lily Zantedeschia aethiopica) while in other species male and female parts are combined in one (i.e. bisexual) flower (e.g. Anthurium, Monstera). In species with unisexual flowers, the male flowers are at the top and the female flowers at the bottom of the spadix.

Leaves

simple or compound
venation parallel, pinnate or palmate
the petiole of the leaf has a membranous sheathing base.
the leaves of the Delicious Monster Monstera deliciosa have large holes in them.

Roots

Adventious

Fruit

A berry, i.e. a fleshy fruit without a stony layer containing one to many seeds.

Publications

Bogner, J. & Nicolson, D.H. 1991. A revised classification of Araceae with dichotomous keys. Willdenowia 21: 35-50.
Brickell, C. (ed.) 1996. The Royal Horticultural Society A-Z Encyclopedia of Garden Plants. Dorling Kindersley, London.
Glen, R.P. 2000. Lemanceae. In: Seed Plants of Southern Africa (ed. O.A. Leistner). Strelitzia 10: 640-641. National Botanical Institute, Pretoria.
Glen, H.F. 2002. Cultivated Plants of Southern Africa. Jacana, Johannesburg.
Mayo, S.J. 1985. Araceae. Flora of Tropical East Africa: 1-71.
Mayo, S.J., Bogner, J. & Boyce, P.C. 1997. The Genera of Araceae. Royal Botanic Gardens, Kew.
Walters, S.M. et al. (eds). Araceae. In: European Garden Flora 2: 75-112.
Singh, Y. 2000. Araceae. In: Seed Plants of Southern Africa (ed. O.A. Leistner). Strelitzia 10: 578-580. National Botanical Institute, Pretoria.