Euclea crispa
| Blue guarri | |
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| Species: | E. crispa[note 1]
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| Binomial name | |
| Euclea crispa (Thunb.) Gürke
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Euclea crispa (blue guarri)[note 2] is an Afrotropical plant species of the family Ebenaceae. This hardy and evergreen plant may form a dense stand of shrubs,[2] or grow to tree size. It is widespread and common in the interior regions of southern Africa,[3] and occurs northward to the tropics. Though some are present near the South African south and east coasts,[4] they generally occur at middle to high altitudes.[5] It is readily recognizable from its much-branched structure and dull bluish foliage colour. Those bearing lanceolate leaves may however resemble the Wild olive,[3] another common species of the interior plateaus.
Range and habitat
It is native to central South Africa (where one of 35 native ebony species),[6] Lesotho, Swaziland, the Zimbabwean plateau and Eastern Highlands,[3] Angola, Zambia, Malawi[2] and uplands of tropical Africa.[4]
It is found in open or thick bush along stream banks,[7] woodland, kloofs, hillsides, open forest, along forest margins and regularly in sheltered rocky places.[3][5] It is rare in the lowveld where it is limited to rocky areas, or areas of higher rainfall.[8]
Habit
It is a rounded, dense and bushy shrub or tree,[7] reaching a height of 2 to 6 metres[7] (rarely 8 to 20 metres),[2][3][4] with a spreading, often symmetrical crown. It is slow-growing like its congeners, and becomes frost and drought resistant with age.[6] In Zimbabwe it is a shrub of 1 to 2 m tall,[2] forming small, dense colonies, or a small tree.[5]
Description
Bole and bark
The bole is single or multi-stemmed and up to 30 cm in diameter.[3] The wood is dark brown, hard and close-grained.[4] The bark varies from grey[7] to brown or blackish,[3] and is smooth in young trees, but rougher in older trees.[2]
Foliage
The plants carry a dense canopy of simple leaves of a dull grey-green colour and a rigid, leathery lineament.[3] Variation in terms of colour, shape, texture and arrangement is however considerable.[3] Foliage colour varies from a greyish green to distinctly blue, and the leaf shape varies from lanceolate to obovate.[3] New branches and foliage are covered in rust-brown scales (gland granules),[2][9] while mature leaves may be hairy or glabrous.[8] Leaves may be opposite, sub-opposite or rarely alternate.[2] The slender petiole is 1.5 to 2 mm long,[2] and the leaves measure up to 5 x 1.5 cm.[8] The leaf veins are clear and transparent against light, unlike the opaque venation of Wild olive trees.[3][7] 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.[4]
Flowers
The fragrant flowers are produced in summer, from October to February.[5] They are small, waxy, pendulous, yellow[8] to greenish-white and borne in axillary pseudo-racemes,[3][8] holding 3 to 10 flowers each.[2] Their bell-shaped corollas are deeply lobed,[2][9] and the ovaries are densely covered in bristles.[2]
Fruit
The roundish, pea-sized berries (4 to 5 mm in diameter)[8] are considered palatable when ripe.[7] They are single-seeded and borne on female trees only.[9] As they ripen, they turn from green to reddish brown, and eventually to black.[2][5][7] They are somewhat or very hairy when green,[2] but more or less glabrous when mature.[8] Saplings can be grown quite easily from fresh, plump seed, that is sown soon after harvesting.[6]
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,[3] margins entire, and generally smaller and narrower[2] than the next
var. ovata
- Range: eastern karroid regions (incl. Cradock and Middelburg) to Northern Cape (incl. Kimberley and Kuruman) and southern Free State
- Description: leaves wavy, much more ovate and sharply tapering, densely hairy when young,[2] sometimes minutely scalloped,[3] and hardly distinguishable from the Mountain guarri where they overlap[2]
Species interactions and uses
Lichens often grow on older bark.[6] Bees are attracted to the sweet scent of the summer flowers, and the leaves provide food for a moth larva, Graphiocephala barbitias. The fruit are eaten by birds and mammals, including antelope, vervet monkeys,[6] mongooses and rats,[4] while the bark and leaves are browsed by Black rhino.[9] A dye extracted from the roots is used for baskets, mats and wool.[9] A medicinal infusion of the root is also used for various ailments,[6] and the fruit or bark are used as a purgative.[3]
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Foliage and bell-like flowers -
Green berries on female tree -
A female tree
Notes
References
- ^ "Euclea crispa (Thunb.) Gürke". The Plant List 2010. Retrieved 15 November 2013.
- ^ a b c d e f g h i j k l m n o p 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 Palmer, Eve (1977). A Field Guide to the Trees of Southern Africa. London, Johannesburg: Collins. pp. 282–284. ISBN 0-620-05468-9. Cite error: The named reference "palmer" was defined multiple times with different content (see the help page).
- ^ 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. 134–135. 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 e 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)