General Info

The evergreen Tree up to 4+m high with grey rough bark. Narrowly elliptic, entire Leaves are simple. Tiny, regular, bisexual Flowers have protruding stamens. Fruit is a small capsule with many Seeds.

Description

Tree

Metrosideros angustifolia.

RSA Tree No. 559.

Common names: Cape-gum, Lance-leaved Myrtle, Smalblaar, Smalblad.

Family: Myrtaceae (Myrtle and Eucalyptus family has 130+ genera and 3 000+ species and includes the Australian genus Eucalyptus, guava and clove). These evergreen trees have simple Leaves that are, leathery, usually entire, gland-dotted and usually opposite. Stipules are very small or absent. Flowers are bisexual and regular. The many Stamens are inflexed in the bud and Anthers are 2-thecous (with 2 pollen sacs). They usually open by lengthwise slits. The usually inferior Ovary has a simple single, capitate (formed like a head) Style and a single capitate Stigma. Fruit is a capsule or berry. Local genera include Eugenia, Heteropyxis, Metrosideros (Western Cape) and Syzygium.

Name derivation: Metrosideros – Greek: metra “the heart or the tree” and sideros “iron” referring to the hard wood in some species.  angustifolia narrow leaved.

Conservation Status: L C (Least Concern). The population is stable. Concern has been expressed about a fungus Holocryphia capensis that attacks this plant. This fungus causes lesions on the branches. This will have to be carefully monitored.

The plant may be a shrub or a small Tree up to 4+m high. Bark is brown to grey rough and moderately flaky, revealing an Orange underbark.

Leaves

The hairless, sub-opposite to opposite, simple (have a single blade which may have incisions that are not deep enough to divide the leaf into leaflets) Leaves on this evergreen tree are entire (with a continuous margin, not in any way indented). The Blade is slightly lighter below. The thinly leathery leaves taper to both the Apex and the Base. They occur in opposite pairs and are elliptic and often very narrow: 9 x 1cm. The Midrib is the only vein that is clearly visible. The Margin is entire and the Petiole (leaf stalk) is short but partly obscured by the decurrent (leaf blades that partly wrap or have wings around the stem or petiole) leaf base. When held up against the sun tiny glands, seen as dots, are visible.

Flowers

The actinomorphic (regular, symmetrical. Perianth, the calyx and corolla, are divisible into 3 or more identical sectors), bisexual Flowers, with white or greenish petals are 5-merous and arise terminally or axillary. They appear collectively in Cymes (a broad, more or less flat-topped, determinate flower cluster, with central flowers opening first) and have a brief presence. The 5 lobed, short Calyx is bell-shaped and the lobes have overlapping edges. There are 5 spreading Petal lobes that are longer than the sepals. The many – 30+ free Stamens are conspicuously yellow, white, or cream coloured and are much longer than the petals. The long Anthers are versatile (hung or attached near the middle, and usually moving freely). The free anthers that are 2-thecous (with 2 pollen sacs) usually dehisce longitudinally. The semi-inferior Ovary is 2-3 chambered. The simple Style is shorter than the stamens (Oct-Feb).

Fruit

The Fruit is a small (3 x 4mm) pale brown, 3-valved Capsule (a dry fruit resulting from the maturing of a compound ovary which usually opens at maturity by one or more lines of dehiscence). It is slightly longer than wide. The persistent calyx partly encloses the capsule from which it may emerge slightly. Each capsule produces many Seeds.

Distribution & Ecology

This tree is endemic (endemism is the ecological state of a species being unique to a defined geographic location, such as an island, nation, country or other defined zone, or habitat type) in the Western Cape and occurs from Clanwilliam (includes the Cedarberg Wilderness area) to the Riversdale district (to the west of Mossel Bay). In this mountainous area, the plant commonly occurs along cliff bases as well as streams, often growing together with wild almond – Brabeium stellatifolium and the willow-like Searsia angustifolia. It thrives in wet acidic soil derived from sandstone.

Ethnobotany

This Plant can help disturbed soil to recover. Current growth forms are rather small to warrant much use to be made of the timber. Sow collected Seeds immediately in sandstone sand after collection. Once germinated they should be planted in full sun and watered regularly. Bonsai growers use the plant.

References

Coates Palgrave, M. 2002. Keith Coates Palgrave Trees of Southern Africa, edn 3. Struik, Cape Town.

Lawrence, G. H. M, 1951. Taxonomy of Vascular Plants, The Macmillan Company, New York. Tenth Printing 1965.

Palmer, E. & Pitman, N. 1972. Trees of southern Africa, Balkema, Amsterdam, Cape Town.

van Wyk, B. & van Wyk, P. 1997 Field guide to Trees of Southern Africa, Struik, Cape Town.

 

http://posa.sanbi.org/flora/browse.php?src=SP

http://pza.sanbi.org/metrosideros-angustifolia

https://link.springer.com/article/10.1007/s13313-016-0399-2

https://www.sciencedirect.com/science/article/pii/S1878614613000342