Ficus L. subg. Urostigma (Gasp.) Miq. sect. Stilpnophyllum Endl.
Description
Trees, mostly hemi-epiphytic, often large.
— The species occurring in Malesia can become trees taller than 30 m, F. hesperidiiformis even up to 60 m tall; F. brachypoda becomes up to 15 m tall. Several Australian species are usually or always hemi-epilithic (lithophytic; Dixon 2001).
internal hairs absent. Leaves spirally arranged, sometimes subdistichous; — The section is characterized by the lamina with the tertiary venation largely parallel to the secondary veins; the primary lateral veins are often slightly stronger than the secondary (and tertiary) ones. Such venation is found in groups of species of other sections of subg. Urostigma (e.g., the species of the F. benjamina-group of sect. Conosycea, F. elasticoides De Wild. of sect. Galoglychia, and F. sphenophylla Standl. of sect. Americana). The stipules are often very long. Some species of the neotropical section of subg. Pharmacosycea, e.g., F. insipida Willd. and F. yoponensis Desv., are strikingly similar to many Stilpnophyllum species in the venation of the lamina and the very long stipules.
Many species show considerable differences in the dimensions of the leaves. These differences occur on individuals, but probably also between individuals (in the same area or geographically separated). Individuals with small leaves tend to bear relatively small figs and often have relatively slender twigs.
stipules often relatively long. stamens 1 (or 2); — The anthers of most species are unusual. They are reniform, covering the apex of the filament and dehiscing with a single slit (subsect. Malvanthera). The anther is even more peculiar in many specimens of F. hesperidiiformis. The thecae are entirely fused forming a thick disc on the filament. This peltate anther opens with an equatorial slit. Such stamens are also known in the neotropical Brosimum alicastrum Sw.; they occur only in subsp. alicastrum, whereas the stamens are normal in subsp. bolivarense (Pittier) C.C. Berg (1972: 170, t. 62). The anthers occasionally have two separate thecae with longitudinal dehiscence (Dixon 2001; see also Fig. 21e). It is likely that the seemingly monothecal anther is formed by two thecae fused over the top of the filament.
Fruits often (partly or entirely) embedded in the inner layer of the wall of the fig or the swollen pedicels.
internal hairs absent. Leaves spirally arranged, sometimes subdistichous; — The section is characterized by the lamina with the tertiary venation largely parallel to the secondary veins; the primary lateral veins are often slightly stronger than the secondary (and tertiary) ones. Such venation is found in groups of species of other sections of subg. Urostigma (e.g., the species of the F. benjamina-group of sect. Conosycea, F. elasticoides De Wild. of sect. Galoglychia, and F. sphenophylla Standl. of sect. Americana). The stipules are often very long. Some species of the neotropical section of subg. Pharmacosycea, e.g., F. insipida Willd. and F. yoponensis Desv., are strikingly similar to many Stilpnophyllum species in the venation of the lamina and the very long stipules.
Many species show considerable differences in the dimensions of the leaves. These differences occur on individuals, but probably also between individuals (in the same area or geographically separated). Individuals with small leaves tend to bear relatively small figs and often have relatively slender twigs.
stipules often relatively long. stamens 1 (or 2); — The anthers of most species are unusual. They are reniform, covering the apex of the filament and dehiscing with a single slit (subsect. Malvanthera). The anther is even more peculiar in many specimens of F. hesperidiiformis. The thecae are entirely fused forming a thick disc on the filament. This peltate anther opens with an equatorial slit. Such stamens are also known in the neotropical Brosimum alicastrum Sw.; they occur only in subsp. alicastrum, whereas the stamens are normal in subsp. bolivarense (Pittier) C.C. Berg (1972: 170, t. 62). The anthers occasionally have two separate thecae with longitudinal dehiscence (Dixon 2001; see also Fig. 21e). It is likely that the seemingly monothecal anther is formed by two thecae fused over the top of the filament.
Fruits often (partly or entirely) embedded in the inner layer of the wall of the fig or the swollen pedicels.
Distribution
Asian mainland present, Australasia, western Malesian region present
Section Stilpnophyllum comprises 20 species. It is the only subdivision of the genus distinctly centred in Australia. The disjunct occurrence of F. elastica in the western Malesian region and the Asian mainland is noteworthy.
Pollination
The pollinators of section Stilpnophyllum belong to the genus Pleistodontes (Wiebes 1994).
A. Berg, C.C. 1972: Olmedieae and Brosimeae (Moraceae). – Flora Neotropica Monograph 7, B. Dixon, D.J. 2001: A chequered history: the taxonomy of Ficus platypoda and F. leucotricha (Moraceae: Urostigma sect. Malvanthera) unravelled. – Austral. Syst. Bot. 14, C. Renner, O. 1907: Beiträge zur Anatomie und Systematik der Artocarpeen und Conocephaleen, insondere der Gattung Ficus. – Bot. Jahrb. Syst. 39, D. Wiebes, J.T. 1994: The Indo-Australian Agaoninae (pollinators of figs). – Verh. Kon. Ned. Akad. Wet., afd. Natk. 92