Ficus L. subg. Urostigma (Gasp.) Miq. sect. Urostigma (Gasp.) Endl. subsect. Conosycea (Miq.) C.C. Berg

Primary tabs

Ficus L. subg. Urostigma (Gasp.) Miq. sect. Urostigma (Gasp.) Endl. subsect. Conosycea (Miq.) C.C. Berg

Description

— All species are essentially hemi-epiphytic, producing more or less extensive secondary aerial root-systems from the base of the trunk, which reach the soil and form anastomosing root-baskets around stems. Others may produce few or numerous aerial roots from the branches and they may develop into pillar-roots. Some species are vigorous and may overpower host-trees, others lack that capacity. The hemi-epiphytic life form allows establishment on rocks or cliffs (as hemi-epilithic). In open places the species can be or become terrestrial.

It is often not clear from label data whether the individuals are hemi-epiphytic (‘stranglers’ or ‘banyans’) or climbers, whether they are primarily or secondarily terrestrial, and what part of the height of the tree consists of the stem and branches or of the ‘stem’ formed by the secondary root-system.

Label date indicate that about 50% of the species are or remain small or medium-sized trees (up to 25 m tall). The other may become tall trees up to 30 or even 40 m tall. In the first category, there are some which can be lianescent and are otherwise treelets or shrubs. The lianescent habit is predominant in F. globosa and F. microsyce.

In contrast to subsect. Urostigma, intermittent growth is not obviously shown in features of the branches. In some species discontinuous growth is obvious as opening-shoots have relatively long stipules (see below). Deciduousness is rare; it occurs in F. calcicola.
Trees, without clear indication of intermittent growth. internal hairs mostly absent (present in few species). Leaves spirally arranged (or subdistichous), (sub)coriaceous, mostly broadest in the middle or above the middle, the margin entire and sometimes callose (towards the base), venation scalariform to reticulate or partly to entirely parallel to the lateral veins; stipules often with a thickened median part. — The stipules often have a thickened median part. These parts are often hairy, but the marginal parts are often glabrous. The margins of the stipules are often involute when dry. In several species, the stipules are much longer and thinner on opening-shoots than on slowly growing shoots.
Ovary mostly partly reddish, sometimes entirely reddish.

Distribution

Asia-Tropical:, Jawa (Jawapresent); Malaya (Peninsular Malaysiapresent); New Guineapresent; Philippines (Philippinespresent); Sri Lanka (Sri Lankapresent); Sumatera (Sumaterapresent) Asian mainland through Malesia to Australia and/or the Solomon Islands: present Australasia: Indian Peninsula: present Madagascar: present Malesian region: present New Guinea to Peninsular India: present Pacific: present Sino-Himalayan region,: present northern Borneo: present
The subsection comprises 66 species. The majority (53) occur naturally in the Malesian region. Twelve species do not occur in the Malesian region, eight of them are species of the Indian Peninsula (some also occurring in Sri Lanka) and two are confined to the Sino-Himalayan region, and two, F. humbertii C.C. Berg and F. menabeensis H. Perrier are endemic to Madagascar. Four species, F. calcicola, F. maclellandii, and F. pubilimba found in the Malay Peninsula, and also the more widespread F. altissima, are essentially Sino-Himalayan extending into this area. On the other hand, thirteen essentially Malesian ones extend into the Sino-Himalayan region.

Two species, as varieties (hillii (F.M. Bailey) Corner and saffordii (Merr.) Corner) included in F. microcarpa (Corner 1960: 398, 399), from the Pacific and Australia, respectively, are in the present treatment regarded as distinct.

The subsection is centred in western Malesia, in the area comprising the Malay Peninsula, Sumatra and northern Borneo; each of these parts has 30-35 species, several of them occurring in the three parts. In the Philippines and Java the number of species is about 20, in all other parts of the Malesian region 10 or less. The number of species (sub)endemic to one of the areas is small, 1, 2 or 3. With only 10 species the subsection is relatively poorly represented in New Guinea, but the number of endemic species (or subspecies) is relatively high and the widespread species represented by more or less distinct forms.

The widespread species, ranging from the Asian mainland through Malesia to Australia and/or the Solomon Islands are F. benjamina, F. drupacea, and F. microcarpa. The disjunct range of F. lawesii extends from New Guinea to Peninsular India.

Most of the species are evergreen and elements of more or less humid forest, some are also found in drier types of forest, as monsoon forest, and they are often deciduous. Some species, as F. calcicola, F. curtipes, and F. maclellandii are often found on calcareous substrates.

Pollination

The following genera of pollinating wasps are found in species of subsect. Conosycea: Deilagaon, Eupristina (Eupristina and Parapristina), Watersoniella (Wiebes 1994). Platyscapa, the genus associated with subsect. Urostigma is found in the Madagascan F. menabeensis (see Berg & Wiebes 1992). The genus Watersoniella appears to be associated with the F. sundiaca-group; other associations are not clear.
A. Berg, C.C. & J.T. Wiebes, African fig trees and fig wasps in Verh. Kon. Ned. Akad. Wet., afd. Natk. 89. 1992, B. Wiebes, J.T., The Indo-Australian Agaoninae (pollinators of figs) in Verh. Kon. Ned. Akad. Wet., afd. Natk. 92. 1994

Taxonomy

Subsection Conosycea differs clearly from subsect. Urostigma in the absence of features related to intermittent growth, such as characteristic differences in length of the internodes, concentrations of persistent stipules (in buds) at the apices of leafy twigs, differences in colour of younger and older parts of the branches. Moreover, the leaves are not articulate or subarticulate and relatively short and thick. Internal hairs are rare and the staminate flowers are always disperse.


Three main groups of species can be recognized:
  1. Ficus benjamina-group (ser. Benjamineae Corner (1960) 374). — Indumentum absent or white and inconspicuous. Lamina small to medium-sized, often drying pale brown to greenish; tertiary venation clearly parallel to the lateral veins (and often with secondary lateral veins, as in F. elastica) and slightly prominent, but clearly visible. Figs are small to medium sized and sessile, initially enclosed by calyptrate bud covers; basal bract often small and unequal.

    The group comprises F. archboldiana, F. balete, F. benjamina, F. kurzii, F. patellata, F. stricta, and F. subcordata, and possibly F. rigo. — The species are very close. Ficus benjamina and F. subcordata are widespread, F. kurzii and F. stricta occur scattered in western Malesia and the mainland, the other species have small areas, mainly in eastern Malesia.
  2. Ficus drupacea-group (subser. Drupaceae, Indicae, and Zygostricheae Corner (1960) 372). — Indumentum brown often conspicuous, at least on the stipules. Lamina large to medium-size; tertiary venation, partly (sub)scalariform or entirely reticulate, often ± prominent. Figs sessile or pedunculate; calyptrate bud covers enclosing young figs are common and often conspicuous; basal bracts are often small and/or caducous.

    The group comprises F. annulata**, F. bracteata*, F. calcicola, F. chrysolepis**, F. consociata*, F. cordatula, F. cucurbitina, F. depressa**, F. drupacea, F. forstenii, F. globosa*, F. kochummeniana*, F. pubilimba, F. retusa*. — The indumentum of the species indicated * consists of dark brown hairs and is mostly floccose. These species constitute a distinct subgroup, like those indicated with ** and have pedunculate figs with the peduncle apically widened into a rim and bearing caducous bracts. — In contrast to the other two groups, the species can be readily distinguished. The group is centred in western Malesia.
  3. Ficus sundaica-group (ser. Callophylleae, Dubiae, Glaberrimae, Perforatae, Subvallidae, and subser. Crassirameae Corner (1960) 373-374). — Indumentum inconspicuous, mostly consisting of whitish and straight hairs, or absent. Lamina mostly small to medium sized, mostly less than 20 cm long, sometimes longer than 20 cm; tertiary venation often partly or largely parallel to the lateral veins, often slightly prominent to flat and then often more or less (to entirely) obscure. Figs sessile, rarely pedunculate (F. glaberrima, F. lawesii, and sometimes in F. microcarpa) and small to large; basal bracts are well developed, coriaceous, and mostly about equal in size (but often different in having a thickened (and/or hairy) median part or in being keeled); they enclose the young figs.

    The group comprises the majority of the Malesian species of the subsection, thus those not listed under the two other groups below. The species of this group are closely related and satisfactory delimitation of the majority of the species is rather tentative because of the absence of solid differentiating characters: most leaf characters are variable as are the size and the shape of the fig receptacle and the basal bracts. Features of the ostiole (open vs closed) are to some extent variable as well. Some species can be easily distinguished, as F. kerkhovenii (with weakly developed basal lateral veins), F. lowii (with distinct colour and structure of the lower surface of the lamina), F. tristaniifolia (with obscure venation of the lower surface of the lamina), or F. subgelderi (with distinctly hairy stipules). For practical reasons the species can be grouped according to the dimensions of the lamina. The species with laminas mostly 5-10 cm long, sometimes up to c. 15 cm long: F. binnendijkii, F. borneensis, F. delosyce, F. microcarpa, F. pallescens, F. soepadmoi, F. spathulifolia, F. subgelderi, F. sumatrana, and F. tristaniifolia. Few species have large leaves (10-)20-35(-40) cm long: F. crassiramea and F. xylophylla. The rest of the species have medium-sized leaves, (5-)10-20(-c. 25) cm long.

Citation

Corner - in Gard. Bull. Singapore. 1960: 272