Euclea crispa
| Euclea crispa | |
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| Species: | E. crispa
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| Binomial name | |
| Euclea crispa (Thunb.) Gürke
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Euclea crispa[2] (Blue guarri) is an Afrotropical plant species of the Ebenaceae family. This hardy and evergreen plant may form a dense stand of shrubs,[3] or grow to tree size. It is widespread and common in the interior regions of southern Africa,[4] and occurs northward to the tropics. Though some are present near the South African east coast,[5] they generally occur at middle to high altitudes.[6] It is readily recognizable from its much-branched structure and dull bluish foliage colour. Those bearing lanceolate leaves may however resemble the Wild olive,[4] another common species of the interior plateaus.
Range and habitat
It occurs in central South Africa (where one of 35 native ebony species),[7] Lesotho, Swaziland, the Zimbabwean plateau and Eastern Highlands,[4] Angola, Zambia, Malawi[3] and northward to tropical Africa.[5] It is found in open or thick bush along stream banks,[8] woodland, kloofs, hillsides, open forest, along forest margins and regularly in sheltered rocky places.[4][6] It is rare in the lowveld where it is limited to rocky areas, or areas of higher rainfall.[9]
Habit
It is a rounded, dense and bushy shrub or tree,[8] reaching a height of 2 to 6 meters[8] (rarely 8 to 20 meters),[3][4][5] with a spreading, often symmetrical crown. It is slow-growing like its congeners, and becomes frost and drought resistant with age.[7] In Zimbabwe it is a shrub of 1 to 2m tall,[3] forming small, dense colonies, or a small tree.[6]
Description
Bole and bark
The bole is single or multi-stemmed and up to 30cm in diameter.[4] The wood is dark brown, hard and close-grained.[5] The bark varies from grey[8] to brown or blackish,[4] and is smooth in young trees, but rougher in older trees.[3]
Foliage
The plants carry a dense canopy of simple leaves of a dull grey-green colour and a rigid, leathery lineament.[4] Variation in terms of colour, shape, texture and arrangement is however considerable.[4] Foliage colour varies from a greyish green to distinctly blue, and the leaf shape varies from lanceolate to obovate.[4] New branches and foliage are covered in rust-brown scales (granule glands),[3][10] while mature leaves may be hairy or glabrous.[9] Leaves may be opposite, sub-opposite or rarely alternate.[3] The slender petiole is 1.5 to 2 mm long,[3] and the leaves measure up to 5 x 1.5 cm.[9] The leaf veins are clear and transparent against light, unlike the opaque venation of Wild olive trees.[4][8] Leaves may also resemble those of the Natal guarri, a species of generally lower altitudes, but the latter's leaves have a finely hairy stalk.[5]
Flowers
They flower in summer, from October to February.[6] The very small, waxy, pendulous flowers are yellow[9] to greenish-white and borne in axillary pseudo-racemes,[4][9] holding 3 to 10 flowers each.[3] The ovaries are densely covered in bristles.[3]
Fruit
The roundish, pea-sized berries (4 to 5mm in diameter)[9] are considered palatable when ripe.[8] They are single-seeded and borne on female trees only.[10] They turn from green to reddish brown, and eventually to black as they ripen.[8][6][3] The fruit are also used as a purgative.[4] Fruit are somewhat or very hairy when green,[3] but more or less glabrous when mature.[9] Saplings can be grown quite easily from fresh, plump seed, that is sown soon after harvesting.[7]
Varieties
var. crispa
- Range: very widely distributed in southern Africa
- Description: leaves variable but hardly wavy, broadly tapering with rounded apex, or acute apex with rounded tip,[4] margins entire, and generally smaller and narrower[3]
var. ovata
- Range: arid karroid regions (incl. Cradock and Middelburg) to Northern Cape (incl. Kimberley and Kuruman) and southern Free State
- Description: leaves wavy and much more ovate and sharply tapering, densely hairy when young,[3] sometimes minutely scalloped,[4] and hardly distinguishable from the Mountain guarri where they overlap[3]
Species interactions and uses
Lichens often grow on older bark.[7] Bees are attracted to the sweet scent of the summer flowers. The fruit are eaten by birds and mammals, including antelope, vervet monkeys,[7] mongooses and rats,[5] while the bark and leaves are browsed by Black rhino.[10] A dye extracted from the roots is used for baskets, mats and wool.[10] A medicinal infusion of the root is also used for various ailments,[7] and the bark is used as a purgative.[4]
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foliage and bell-like flowers -
green berries on female tree -
a female tree
References
- ^ "Euclea crispa (Thunb.) Gürke". The Plant List 2010. Retrieved 15 November 2013.
- ^ crispa = "curled", referring to the leaf margins that may be rolled under or wavy
- ^ a b c d e f g h i j k l m n o Palgrave, Keith Coates (1984). Trees of Southern Africa. Cape Town: Struik. pp. 736–737. ISBN 0-86977-081-0.
- ^ a b c d e f g h i j k l m n o p Palmer, Eve (1977). A Field Guide to the Trees of Southern Africa. London, Johannesburg: Collins. pp. 283–284. ISBN 0-620-05468-9.
- ^ a b c d e f Pooley, Elsa (1997). Trees of Natal, Zululand and Transkei. Durban: Natal Flora Publications Trust. p. 398. ISBN 0-620-17697-0.
- ^ a b c d e Hyde, Mark; et al. "Euclea crispa (Thunb.) Sond. ex Gürke subsp. crispa". Flora of Zimbabwe. Retrieved 18 November 2013.
{{cite web}}: Explicit use of et al. in:|first=(help) - ^ a b c d e f Stoll, Nicolette (Aug 2010). "Euclea crispa (Thunb.) Gürke subsp. crispa". plantzafrica.org. Retrieved 15 November 2013.
- ^ a b c d e f g Tree Society of Southern Africa (1974). Trees and Shrubs of the Witwatersrand. Johannesburg: Witwatersrand University Press. pp. 124–135. ISBN 0-85494-236-X.
- ^ a b c d e f g Van Wyk, Piet (1984). Field Guide to the Trees of the Kruger National Park. Cape Town: C. Struik. p. 224. ISBN 0-86977-221-X.
- ^ a b c d Van Wyk, Braam; et al. (1997). Field Guide to Trees of Southern Africa. Cape Town: Struik. p. 340. ISBN 1-86825-922-6.
{{cite book}}: Explicit use of et al. in:|first=(help)