Weinmannia fraxinea
Description
Small to large tree, up to 25(-40) m high.
Leaves imparipinnate with (0-)1-8 pairs of lateral leaflets;
Stipules ± orbicular, subreniform or broadly spathulate, 0.8 by 0.8 to 1.5 by 1.8 cm.
Inflorescence 1-3 opposite pairs of lateral dyads or tetrads;
Flowers unisexual or hermaphrodite;
Capsules with valves 2.5-4(-6) by 1.5-2(-3.1) mm at dehiscence;
Seeds 0.8-1.1 mm long, comose at both ends, hairs up to 2 mm long.
Distribution
Asia-Tropical: Malaya (Peninsular Malaysia present); New Guinea present; Philippines (Philippines absent); Sulawesi (Sulawesi absent); Sumatera (Sumatera present); Thailand (Thailand present), Solomon Islands present
Solomon Islands and Malesia: from Peninsular Malaysia, Thailand and Sumatra to New Guinea; absent from Sulawesi and the Philippines.
Ecology
. At lower elevations in primary and secondary forest, and locally common as a small to medium tree above 500 m. At higher altitude in mossy montane forest, heath forest, and subalpine shrubbery. Varying in abundance from uncommon to one of the main constituents of montane forest. On various substrates including young volcanic soils, open, stony ground, sometimes recently burnt and dominated by ferns. Occasionally on soils derived from ultramafics and on acidic, water-logged sands and in mixed peat swamp forest at sea level (Borneo).
Morphology
2. Field characters: Small, often shrub-like tree 5-15 m tall at high altitude, to a tall, slender tree up to 25(-40) m high by 50 cm dbh at lower altitude. Buttresses usually absent. Flowers white, yellowish, pale green or pale pink, occasionally bright pink.
1 The breeding system can be dioecious or hermaphrodite, or very rarely polygamodioecious, and the proportion of individuals bearing flowers with different sexual expression varies geographically (largely dioecious in Western Malesia, dioecious in the Moluccas, largely hermaphrodite in New Guinea and the Solomon Islands). Variation in the breeding system, as deduced from the morphology of the flowers, is not correlated with variation in any other morphological characters.
Taxonomy
This is the most widespread and abundant Weinmannia in Malesia. The leaflets are variable in number, size, shape, texture and indumentum, but usually they are broader towards the unequal base and the apex is acuminate. The inflorescence of dyads and tetrads is often well developed. The name W. blumei has often been applied to this taxon in western Malesia. Closely related satellite species which are maintained as distinct for the present include W. devogelii (Sulawesi), W. hooglandii (Peninsular Malaysia) and W. macgillivrayi Seem. (Vanuatu).
The majority of collections from throughout the range have medium-sized, chartaceous to subcoriaceous leaflets, with medium-sized and usually caducous stipules, and the indumentum on the axes varies from puberulent to tomentose. At high altitudes, leaflets tend to be smaller, the largest lateral leaflet per leaf exceptionally as small as 2.2 by 0.9 cm, and the inflorescences tend to be shorter and less well developed. At medium elevations, some collections from Sumatra to New Guinea have exceptionally large leaflets, up to 12 by 3.5 cm, that vary in texture from chartaceous to coriaceous. When coriaceous, they often have minutely prominent or contrastingly coloured venation and a dense reticulum, the axes are glabrous or subglabrous, sometimes with an almost rubbery consistency, and the stipules are larger and more persistent. Elsewhere there are variants with lanceolate leaflets (especially in the Moluccas).
Distinct variants can sometimes be recognised at a local level but they tend to intergrade when the whole range of W. fraxinea is considered. Similar morphologies can be found in widely separated localities, while other variants occur in only one region. In some cases, there appear to be two distinct variants which do not intergrade, although in another locality they appear to do so. In this type of polymorphic, non-hierarchical variation, where characters vary independently of one another and largely independently of geography and ecology, formal infraspecific taxa are unwarranted although it may sometimes be useful to apply informal ‘nicknames’ to distinguish between variants as has been done for some other ochlospecies (e.g. ). However, there are too many intermediate collections for nicknames to be applied consistently to all the material in W. fraxinea.
The majority of collections from throughout the range have medium-sized, chartaceous to subcoriaceous leaflets, with medium-sized and usually caducous stipules, and the indumentum on the axes varies from puberulent to tomentose. At high altitudes, leaflets tend to be smaller, the largest lateral leaflet per leaf exceptionally as small as 2.2 by 0.9 cm, and the inflorescences tend to be shorter and less well developed. At medium elevations, some collections from Sumatra to New Guinea have exceptionally large leaflets, up to 12 by 3.5 cm, that vary in texture from chartaceous to coriaceous. When coriaceous, they often have minutely prominent or contrastingly coloured venation and a dense reticulum, the axes are glabrous or subglabrous, sometimes with an almost rubbery consistency, and the stipules are larger and more persistent. Elsewhere there are variants with lanceolate leaflets (especially in the Moluccas).
Distinct variants can sometimes be recognised at a local level but they tend to intergrade when the whole range of W. fraxinea is considered. Similar morphologies can be found in widely separated localities, while other variants occur in only one region. In some cases, there appear to be two distinct variants which do not intergrade, although in another locality they appear to do so. In this type of polymorphic, non-hierarchical variation, where characters vary independently of one another and largely independently of geography and ecology, formal infraspecific taxa are unwarranted although it may sometimes be useful to apply informal ‘nicknames’ to distinguish between variants as has been done for some other ochlospecies (e.g. ). However, there are too many intermediate collections for nicknames to be applied consistently to all the material in W. fraxinea.