Ficus subg. Synoecia

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Ficus subg. Synoecia

Description

— The subgenus is characterized by the habit described above and resembling that of Ivy (Hedera helix, Araliaceae). However, bathyphylls can be ill-defined, as in F. laevis. They may be totally absent, as in F. spiralis. True acrophylls may usually not develop or transitional features may be dominant, as in representatives of the F. punctata-group. Bathyphylls are usually smaller and thinner than acrophylls, the indumentum often consists of smaller hairs, and may be asymmetric in contrast to (true) acrophylls. Asymmetric bathyphylls are found in (all or most) members of sect. Kissosycea and in F. pumila, whereas they are (always?) symmetric in the other members of the subgenus. Some of the variation of material in the acrophyll-state can be related to the retainment of features of the bathyphyll-state. Not only the asymmetric laminas can be explained by retainment of traits of the bathyphyll state, but also some of the variation in the indumentum, as that consisting (predominantly) of stiff and straight hairs and that consisting (predominantly) of soft and crinkled hairs, a type of hairs usually present in the bathyphyll-state. Features of the bathyphylls are not included in the present descriptions of the species. Herbarium material with bathyphylls is frequently lacking or it cannot be related (with certainty) to fertile material. On branches with bathyphylls, the stipules are mostly (sub)persistent, whereas usually caducous on those with acrophylls, and they can be basally connate. Thick climbing stems or branches are often quadrangular and smaller ones often ± compressed. Roots are often also found on branches with acrophylls, apparently when they get in touch with the ‘substrate’.
Root-climbers, with climbing stems and branches, with short roots on the nodes and internodes, and often non-rooting branches, bearing the figs. Leaves on rooting branches (bathyphylls) in size, shape and texture mostly different from those on non-rooting (and fertile) branches (acrophylls), or sometimes with transitional features, the leaves alternate, mostly distichous, sometimes in lax spirals; — The leaves are usually distichous, but sometimes arranged in lax spirals, at least on branches with acrophylls. The lamina is symmetric in the true acrophyll-state, but they can be clearly asymmetric or only so at the base, apparently due to retainment of characters of the bathyphyll-state. The lamina usually has a hydathode-like structure at the top of the acumen, often in a minute notch. The margin is entire and mostly ciliolate. In several species the lower surface is foveolate, however, in different ways. In the F. punctata-group of sect. Kissosycea, the areoles (stomatal pits) are surrounded by flat, in dry material pale-coloured tissue, (largely of the veinlets), and the rims bear minute hairs. The stomatal pits are brownish when dry. In the F. excavata-subgroup, the stomatal pits are small and surrounded by low rims without contrasting colour and without hairs on the rims. This type of stomatal pits is associated with minutely bullate areoles. In F. pumila (and the related Asian mainland species F. sarmentosa Buch.-Ham. ex Sm. p.p.), the areoles are surrounded by very prominent veinlets, and the stomatal pits ± deeply sunken, but in F. sarmentosa (p.p.) the foveolate lower surface of the lamina may also resemble that of species of the F. punctata-group. In other species of sect. Kissosycea, the lower surface of the lamina is tessellate, when dry with large brownish-coloured areoles surrounded by pale-coloured tissue. In the F. punctata-group, tessellate laminas represent apparently a state transitional between the bathyphylls and the acrophylls with a foveolate lower surface. Laminas without marked areoles, tessellate ones and foveolate ones can be found in the same collection (F. barba-jovis). Faintly tessellate lower surfaces may occur in some species of sect. Rhizocladus.

The epidermis of the petioles is flaking off in most species.
stipules fully amplexicaul, free, on climbing branches usually (sub)persistent. — The staminate and neuter flowers are disperse in the majority of the species, ostiolar in a smaller number.

Neuter and staminate flowers are very abundant in large figs of the F. punctata-group. They have long pedicels and the perianths occur at the same level as the stigmas. Intermixture of these perianths and stigmas prevents that the stigmas form a continuous layer as can be commonly found in small figs (of the same group) with shorter neuter flowers. In the species with numerous staminate and neuter flowers, the perianths of these flowers form the coherent (almost closed) surface from where the pollinators oviposit. In F. laevis and F. pubigera the long interfloral bristles separate the stigmas and their tips form with the stigmas the closed surface.

The number of staminate flowers can also be high in species with ostiolar staminate flowers (e.g., in F. jacobsii and F. pumila).

Neuter flowers are sometimes absent (F. apiocarpa) as are short-styled flowers and then only staminate flowers are present in the inflorescence.

In the F. apiocarpa-group (of sect. Kissosycea) the staminate flowers are disperse in some species and subspecies and ostiolar in others: F. disticha var. calodictya, F. distichoidea, and F. phatnophylla.

The tepals are mostly red, often dark red; they are always or often pink or sometimes yellowish to whitish in subsect. Trichocarpeae. The tepals are sometimes indurated (F. bakeri).

Flowers in large figs can be up to 1 cm long (e.g., in F. odoardii) or may have long pedicels (e.g., in F. punctata).
Staminate and neuter flowers scattered among the pistillate ones or near the ostiole. Stamens 1, 2 (or 3), apiculate or not; Ovaries often stipitate, those of the long-styled flowers whitish to yellowish, those of the short-styled flowers (dark) red-brown or white to yellowish. — The fruits are usually compressed with a keel all around, but in some species (as F. gymnorygma, F. pubigera, and F. scratchleyana) the fruit is not compressed and the keel is lacking or faintly developed.
Fruits yellowish, usually ± compressed and keeled all around.

Distribution

Asia-Tropical:, Borneopresent; New Guineapresent; Sri Lanka (Sri Lankapresent) Asian mainland: present Micronesia: present N Australia: present Sino-Himalayan region: present Solomon Islands: present from Myanmar to the Solomon Islands: present from the Andaman Islands to the Carolines: present
The subgenus comprises c. 72 species, of which 61 occur in Malesia. Ficus nasuta Summerh. is endemic to the Solomon Islands and F. diversiformis Miq. to Sri Lanka, and c. 10 species are elements of the Sino-Himalayan region. Two essentially Sino-Himalayan species, F. laevis and F. pubigera, extend into the Malesian region. The majority of the 61 found in Malesia are confined to this region. Seven of them extend outside the region, either to the Micronesia, the Solomon Islands and/or N Australia or to the Asian mainland; the most widespread of them are F. disticha (ranging from Myanmar to the Solomon Islands) and F. sagittata (ranging from the Andaman Islands to the Carolines). Borneo with 25 species mainly in its northern part and New Guinea with 26 species mainly in its eastern part are clearly centres of the subgenus. The majority of the Bornean species belong to sect. Kissosycea and the majority of the New Guinean ones to sect. Rhizocladus. About 2/3 of the species are lowland species, the others are montane or submontane, or a few occurring at both high and low elevations.

Pollination

The pollinators of the species of subg. Synoecia belong to the genus Wiebesia (Wiebes 1994: 99-116).
A. Corner, E.J.H., Taxonomic notes on Ficus Linn., Asia and Australasia. V. Subgen. Ficus sect. Rhizocladus, Kalosyce, Sinosycidium, Adenosperma, and Neomorphe. in Gard. Bull. Singapore 18. 1960, B. Wiebes, J.T., The Indo-Australian Agaoninae (pollinators of figs) in Verh. Kon. Ned. Akad. Wet., afd. Natk. 92. 1994

Anatomy

— Two main types of hairs can be distinguished: weak and more or less crinkled hairs, which may form a floccose indumentum, and stiff hairs, which are often septate and often have ± swollen bases. In some species the stiff hairs are irritant; they easily break off from the swollen bases and are not septate. The (mostly brown) pluricellular hairs are mostly peltate, but are oblongoid-capitate in subsect. Rhizocladus and subsect. Pogonotrophe. A hypodermis is lacking in the latter subsection.

Citation

Miq. - in Fl. Ind. Bat. 1859: 328