A STUDY ON THE TAXONOMY OF SOME STOLONIFLOROUS SPECIES OF FICUS SUBSECTION SYCOCARPUS (MORACEAE) IN THAILAND AND MALESIA

The taxonomy of several, mainly stoloniflorous, Ficus species from Thailand and Malesia is revised resulting in a new species, F. bukitrayaensis C.C. Berg and two new names, F. malayana C.C. Berg & Chantarasuwan and F. ridleyana C.C. Berg & Chantarasuwan. Ficus megaleia Corner and F. unci­ nata (King) Becc. are redefined and F. heterostyla Merr. is reinstated. Ficus arfakensis King and F. scortechinii King are reduced to synonyms of F. ribes Blume.


INTRODUCTION
Ficus subg. Sycomorus of Thailand and the Malay Peninsula comprises five stoloniflorous (or flagelliflorous) species: Ficus beccarii King, F. heterostyla, F. malayana, F. ridleyana and F. semicordata Buch.-Ham. ex Sm. Three of them are based on varieties of which two were already regarded as problematical in connection with the preparation of the Ficus treatment for Flora Malesiana (Berg & Corner, 2005) as varieties in F. uncinata (King) Becc. and F. vrieseana Miq., and because of the differences with the other varieties not included in the Flora Malesiana treatment. Further studies, primarily on behalf of the Flora of Thailand, led to a revision of the stoloniflorous species in this peninsular part of Asia. It also led to the redefinition of F. ribes Blume, a potentially stoloniflorous species in the region and to the re-evaluation of the Bornean material included in F. uncinata.

Ficus beccarii King
The description as presented in Flora Malesiana (Berg & Corner (2005) The species is now known in Thailand as well; both in Peninsular Malaysia and Thailand the narrow-leaved form of the species is represented. Shrub or tree up to 5(-8) m tall. Leafy twigs 2.5-10 mm thick, whitish puberulous, intermixed with patent dark brown to purplish longer hairs, usually with pairs of nodal waxy glands on the nodes; internodes hollow; periderm sometimes flaking off. Leaves (sub)opposite or distichous; lamina elliptic to subovate, 5.5-27 by 2-11 cm, symmetric or slightly asymmetric, chartaceous, apex acuminate, base rounded to truncate to obtuse, margin dent(icul)ate at least towards the apex; upper surface whitish hirtellous to hispidulous, scabrous, lower surface whitish puberulous to subtomentose on the veins, on the main veins intermixed with longer patent to ± appressed dark brown to purplish hairs, scabridulous, cystoliths only beneath; lateral veins (4-)6-8 pairs, the basal pair usually branched, 1/10-1/6 the length of the lamina, other lateral veins often branched or furcate away from the margin, tertiary venation scalariform, ± prominent beneath; waxy glands of lateral vein in the middle of the lamina, minute (or absent); petiole 1-6 cm long, whitish puberulous, intermixed with long patent dark brown to purplish hairs, the epidermis flaking off; stipules 0.5-2 cm long, brown (sub)sericeous, caducous. Figs on branched or unbranched rooting stolons, 2-4 m long with up to 10 cm long internodes, mostly arising from the base of the trunk, sometimes not only arising from the base of the trunk but also higher on; peduncle 0.1-0.3 cm long; basal bracts 3, verticillate, 1-2 mm long; receptacle subglobose, 0.8-1.7 cm diam. when dry, up to 1.6-2.2 cm diam. when fresh, non-stipitate or up to 0.5 cm long stipitate, faintly ribbed, dark brown hirtellous, without lateral bracts, orange red to brownish at maturity, apex convex, ostiole c. 2 mm diam., surrounded by 5 apical bracts; internal hairs absent. Distribution -Thailand, Laos, Cambodia, Vietnam.

Ficus heterostyla
Habitat -Evergreen forest, often secondary growth, at low altitudes. Notes -1. The species is related to F. hispida L.f. from which it differs in the stoloniflory, the dark brown indumentum on leafy twigs and other parts, the smaller fig receptacles without lateral bracts, persistent indumentum turning mostly brownish at maturity. At least in the region where the two species co-occur, F. hispida is predominantly cauliflorous with sometimes short (up to 40 cm long) fig-bearing branchlets at the base of the trunk, the figs have longer peduncles, and the receptacles bear (mostly) lateral bracts and turn yellow at maturity. However, dark brown to brownish (patent or appressed) indumentum is found in collections of F. hispida from Sri Lanka, South India and South China and that indumentum is apparently associated with stoloniflory. This form of F. hispida differs from F. heterostyla on the (usually) obovoid to pyriform receptacle with lateral bracts and figs ripening yellowish and in the peduncles longer than 0.3 cm. The figs may also be borne on the trunk on short branchlets and stolon-like branches may not bear figs at all. The considerable variation of F. hispida in continental Asia needs further attention.
2. The type of F. hispida L.f. var. rubra Corner (1960: 54) from Vietnam, Thu Inh, N of Koutume, Poilane 32047 (holo P; iso L) of which the indumentum is whitish, matches the brown-hairy material described above in most other features and is probably a white-hairy form as occurs in other brown-hairy Sycocarpus species; the figs are or become glabrous.
3. This species shows also similarities to F. ridleyana, as in the rather small globose receptacle without lateral bracts and in the indumentum. It is distinct in the frequently opposite leaves, usually with a slightly asymmetric lamina without a cordate base at the broad side; moreover, the acumen of the lamina is shorter.  Shrub or tree up to 10 m tall. Leafy twigs 2 -4 mm thick, ± angular to subterete, brown(ish) hirtellous to subhirsute or strigillose with hairs all of similar length, sometimes intermixed with sparse shorter hairs, the long patent hairs with swollen bases, and mostly (re)curved; nodal waxy glands absent or present; internodes hollow; periderm persistent. Leaves (sub)distichous; lamina oblong to subobovate, (9-)15-30(-45) by (3-)6-17 cm, asymmetric, chartaceous, apex acuminate, base cuneate to cordate at the broad side, the lobe not covering part of the petiole (and leafy twig), cuneate to subcordate at the narrow side, margin denticulate (to dentate) at least towards the apex or (sub)entire; upper surface brownish hirtellous to hispidulous or appressed-puberulous, sometimes only on the midrib, ± scabrous to smooth, lower surface brownish hirtellous or strigillose to appressed-puberulous on the veins, the hairs mostly all of similar length, sometimes intermixed with sparse shorter hairs, scabridulous, cystoliths only beneath; lateral veins (5-)6-7 or 8-10 pairs, the basal pair (at least) at the broad side branched (or unbranched), none or one or two of the others furcate away from the margin, tertiary venation scalariform; waxy glands in the axils of some lateral veins in the middle part of the lamina, small; petiole 0.5-1.5(-2.5) cm long, brownish hirtellous to subhirsute or appressed-puberulous, the hairs usually of similar length, the epidermis persistent; stipules 1-2.5 cm long, brownish hirtellous to substrigose or appressed-puberulous, caducous or subpersistent. Figs on branched, up to 10 m long, rooting stolons arising from the base of the trunk (or 1.5-2 m from the base) and with up to 10 cm long internodes; peduncle 0.1-0.4 cm long; basal bracts 3-6, (sub)verticillate, 2-4 mm long, ± appressed; receptacle subglobose, 1.5-2(-3) cm diam. when dry, 3-3.5 cm diam. when fresh, brown puberulous to hirtellous, with numerous appressed lateral bracts, these whitish to brownish appressed-puberulous to strigillose, ochraceous at maturity, apex convex to flat; ostiole 2-3 mm diam., more or less hidden in the indumentum, surrounded by 3-5 apical bracts; internal hairs absent. Longstyled flower with glabrous style and the perianth absent. Distribution -Thailand (peninsular), Sumatra (only Lingga Islands), Peninsular Malaysia, Borneo: Brunei, Kalimantan, Sabah, Sarawak.

Ficus malayana
Habitat -Evergreen forest, at altitudes up to 1200 m. Notes -1. Two forms can be distinguished within the species: -form a: with patent hairs, as on the leafy twigs; it occurs throughout the range of the species and comprises the type of F. uncinata (King) Becc. var. strigosa. -form b: with appressed hairs, as on the leafy twigs; it is limited to Borneo and comprises the types of F. uncinata var. subbeccarii and var. truncata. 2. The presence of patent and appressed hairs on various parts is found in several (stoloniflorous) species, including F. vrieseana Miq.
3. In material from Thailand, Sumatra and Peninsular Malaysia, the margin of the lamina is denticulate (to dentate), often from the base to the acumen and none of the lateral veins above the basal ones is furcate away from the margin. In Borneo, the margin of the lamina is entire to only (faintly) denticulate in the uppermost part and often one (or two) lateral veins above the basal ones furcate away from the margin. Moreover, the number of lateral veins is smaller, usually 6 or 7 pairs, whereas 8 pairs or more elsewhere

Ficus ribes Reinw. ex Blume
Ficus ribes Reinw. ex Blume (1825)  The description of the species as presented in Flora Malesiana remains largely unchanged, with the exception of the distribution of cystoliths in the lamina. They occur either both above and beneath or only beneath material. The two morphs have been recognized as species: F. ribes and F. scortechinii (see Berg & Corner (2005) 446, 451). Re-examination of material on behalf of the treatment for the Flora of Thailand led to the decision to unite them. The presence of cystoliths in the upper surface of the lamina may vary from abundant to (nearly) absent or cystoliths may even occur only above. Material with cystoliths on both sides is predominant in Sumatra and Java, rare in the Malay Peninsula and Thailand. The decision to unite the material under two species names implies that also F. arfakensis from the Moluccas, New Guinea and the Solomon Islands (see Berg & Corner (2005) 397) needs to be included in the species due to lack of satisfactory differentiating morphological characters. The consequence is establishment of a clearly disjunct species, rare in the genus.
In Thailand (and also always? in Peninsular Malaysia) the figs are cauliflorous, mostly born on branchlets at the base of the trunk, often also partly in the soil. In Sumatra and in Java the fig-bearing branches often become stolon-like, up to 1 m long, and the fig receptacle can be larger, up to c. 1.5 cm in diam. when dry and (also) depressed-globose.

II. Stoloniflorous species in Borneo
In the wake of the revision of the stoloniflorous species found in Thailand and Peninsular Malaysia, the same group of species in Borneo had to be re-examined which leads to the conclusion that F. uncinata, as defined by Corner (1960) and as such adopted for the Flora Malesiana treatment (Berg & Corner, 2005) comprises four species: 1) Ficus malayana, treated above, comprising some of the collections listed under F. uncinata var. strigosa (Corner, 1960) and the types of var. subbeccarii (Corner (1962) and var. truncata Corner (1960); 2) Ficus uncinata s.str., comprising most of the collections identified as F. uncinata var. uncinata and the type of var. gracilis; 3) Ficus megaleia Corner (1960Corner ( , 1962, also comprising some of the collections identified as F. uncinata var. pilosior Corner (1960) and var. strigosa Corner (1960); 4) an undescribed species, F. bukitrayaensis C.C. Berg, comprising for the greater part more recent collections, not yet listed by Corner (1960), andF. uncinata var. parva Corner (1960). Also the treatment of F. uncinata in the Tree Flora of Sabah and Sarawak (Kochummen, 2000) indicated heterogeneity. The key also comprises F. geocharis Corner, F. stolonifera King and F. subterranea Corner; in all these species the long-styled flower lacks a perianth and has a glabrous style, except for F. stolonifera with a hairy style and a short collar-shaped perianth. Ficus treubii King is also included in the key as it can be stoloniflorous and has the fig receptacle usually with 1 or 2 lateral bracts. Fico geochariti similis, fici receptaculo glabro maturitate albescenti, folii lamina basi lobo non-auriculato, acumine breviore differt. -Typus: Veldkamp 8601 (holo L), Indonesia, Kalimantan, Bukit Raya, Batu Badinding, KCT, 50 m, 8 Feb. 1983.
Habitat -Evergreen forest, at low altitudes.
Notes -1. This species shows close affinities to F. geocharis, from which it differs in the (sub)glabrous fig receptacle, shorter and glabrous bracts, the shorter acumen of the lamina (1.5-2 vs (2-)3-6 cm) and the different base of the broad side of the lamina: not a narrow auriculate strip along the petiole.
2. It also resembles the small-leaved form of F. megaleia, from which it differs in the shorter petiole, mostly also in the smaller lamina, and, moreover, in the shorter and glabrous bracts of the fig.
3. The type of Ficus uncinata var. parva (Corner, 1960) and Harrison 0197 from Sarawak, Lambir Hills National Park are distinct in the predominantly white colour of the indumentum on vegetative parts.
4. The colour of the mature figs is mostly white or whitish or (partly) greenish if exposed on the soil surface. However, some labels describe the figs (partly) red or maroon. 5
Habitat -Evergreen forest at altitudes up to c. 2000 m. Notes -1. The species comprises two main forms which differ in size of the lamina, length of the petiole and shape of the lobe of the base of the lamina at the broad side: -form a: lamina mostly 35-50 cm long, petiole mostly 1.5-3 cm long, lobe of the base of the lamina at the broad side mostly partly covering the petiole and leafy twig; -form b: lamina mostly 15-30 cm long, petiole mostly 0.7-1.5 cm long, lobe of the base of the lamina mostly not covering the petiole and/or reaching the leafy twig. The collections made can be roughly sorted on the basis of these differences. Although the majority of collections which can be included in form a are made on Mt Kinabalu at altitudes between 1200-2000 m, the two forms cannot be distinguished satisfactorily on geographical nor on ecological criteria.