Erycibe brunneopilosa Kochaiph. & Utteridge, 2021

Kochaiphat, Phongsakorn, Traiperm, Paweena & Utteridge, Timothy M. A., 2021, Three new species of Erycibe (Convolvulaceae) from Malesia, Phytotaxa 494 (1), pp. 103-112 : 108-109

3. Erycibe brunneopilosa Kochaiph. & Utteridge sp. nov. ( Figs. 1 and 4 )

Type:— MALAYSIA. Borneo: Sarawak, 5 th Division, along Sungai Masia in the Maligan Range , Lawas [4°37’42.0”N, 115°33’22.5”E], 3100 ft. [1030 m], 8 March 1973 (fl.), Tong S.32819 (holotype K!; isotypes BO!, KEP!, L [ L.2734271]!, SAN) .

Diagnosis:—Unique in the genus Erycibe for the combination of the climbing habit with all parts hairy, the leaves covered with stellate 5–8 branched hairs, the longest central hair branch up to 0.75 mm, the sepals densely hairy abaxially and fruits densely covered with red-brownish hairs up to 2 mm long.

Climber up to 30 m; stems terete, young branches densely brownish stellate-hirsute with 6–8-branched hairs, mature stem nearly smooth, greyish, not lenticellate. Leaves simple, petioles 0.6–1.1 cm long, densely dark-brownish hairy; lamina coriaceous, elliptic, elliptic-oblong to lanceolate 4–17.5 × 1.7–6.5 cm, base obtuse, apex acuminate-caudate, margin entire, revolute, adaxially nearly glabrous, abaxially stellate-hirsute with 6–8-branched hairs, the longest central branch up to 0.75 mm long; midrib appressed adaxially, prominent abaxially; veins 5–10 on either side, inconspicuous adaxially, prominent abaxially; intercostal veins reticulate, inconspicuous adaxially, prominent abaxially. Inflorescences axillary, comprising short, 3–10-flowered glomerules, up to 1.5 cm long; floral bracts lanceolate, 1–3.5 mm long; pedicels very short, up to 1.5 mm long, densely stellate-hairy with 6–8-branched hairs, the longest central branch 0.3–0.7 mm long; sepals equal, deltate or ovate, 2.0–3.0 × 1.5–3.0 mm, densely stellate-hairy abaxially, glabrous adaxially, margin ciliate; corolla tube 1–1.5 mm, midpetaline bands densely stellate-hairy abaxially, longitudinal veins inconspicuous, lobule c. 2.5 × 1.5 mm, margin entire; stamens c. 2 mm long, filaments broader at the base, anthers yellowish when dry, c. 1.3 mm long, base cordate, apex acuminate; ovary (dry) ovoid, c. 1 × 1.5 mm, covered with hairs on upper half below stigma, stigma 5-ridged, c. 0.7 mm tall. Fruit a berry, ±ovoid, c. 1.8 × 2.4 cm, covered with red-brownish hairs up to 2 mm long.

Distribution:— Endemic to Borneo and the Malaysian states of Sarawak and Sabah.

Habitat:— Climber reaching 100 ft [30 m] high on trees, on open hill slopes with sandy soil in mixed deciduous forest or lowland forest in logging areas; elevation 300–1030 m.

Preliminary conservation assessment:— Endangered (EN) [B1a+b(iii, iv)] based on IUCN (2012) categories. It has an Extent of Occurrence (EOO) of 2,751 km 2 (<5,000 km 2, fulfilling the B1 criterion), and is known to exist at no more than five locations. The estimated Area of Occupancy (AOO) for this species is 16 km 2 using a 2 km 2 grid base. The species has been collected in logging areas, and the quality of the habitat will decline in such areas with a projected decline in the number of locations, especially as the species has not been re-collected from the Bintulu location since 1972 and satellite imagery shows the effects of oil palm plantations and logging in that locality.

Phenology:— Flowering in March, fruiting in September.

Etymology:— The epithet is from the Latin, ‘brunneis’ and ‘pilosus’ referring to the brown hairs covering the plant, conspicuous in vivo and noted on all collecting labels, for example, ‘Twigs white, while young covered in brown hairs. Under-leaf surface covered in brown hairs. Flowers in bud, covered with brown hairs’ (Tong S.32819).

Notes:— Erycibe brunneopilosa is unique in the genus for the combination of the brown hairs on all parts, the climbing habit, elliptic to lanceolate leaves, the axillary inflorescences with 3–10 flowers and especially the densely hairy fruits with hairs up to 2 mm long. This new species would key to E. citriniflora Griff. ( Griffith 1854: 284) in Hoogland (1953a) based primarily on the acute anthers, hairy sepals, indumentum type and smooth branches. Erycibe citriniflora is a commonly encountered species in Thailand and Peninsular Malaysia but differs from E. trichogyne in the usually larger leaves 8–30 × 3–11 cm and the glabrous or sparsely appressed-hairy fruit. Erycibe brunneopilosa is also similar to E. magnifica Prain (1904: 18) , endemic to Peninsular Malaysia, in the climbing habit, densely hairy leaves and fruit, but differs in the stellate-hirsute adaxial leaf surface with appressed midribs, while E. magnifica has a stellate-villous adaxial leaf surface with strongly sunken midribs. In addition, Hoogland (1953c) uses the thick clubshaped corolla lobules of E. magnifica as a key character, but the corolla lobules of E. brunneopilosa are much thinner and not club-shaped.

This newly described species is one of the Erycibe species with dense hairs on the fruit. In Borneo, it is only likely to be confused with the climbing taxa with hairy fruits E. grandifolia Merr. ex Hoogland (1953a: 313) and E. villosa . Erycibe brunneopilosa differs from E. grandifolia in the short (up to 1.5 cm long) axillary inflorescences (terminal to 20 cm long in E. grandifolia ) and the fruits with simple hairs to 2 mm long (rather than very short stellate hairs on the fruit of E. grandifolia ); it differs from E. villosa in the lamina morphology (elliptic, elliptic-oblong to lanceolate, 4–17.5 cm long and with scattered hairs below not obscuring the lamina surface versus obovate to elliptic, 8–11.5 cm long and with the abaxial lamina densely covered with persistent woolly hairs in E. villosa ) and the much shorter hairs on the fruit, up to 2 mm long whereas they are c. 6 mm long in E. villosa . Erycibe brunneopilosa is also very similar to E. trichocarpa by its leaf morphology and the hairs on the stems and fruits, but E. trichocarpa differs in the tree habit and also has shorter hairs on the vegetative parts, only 0.15–0.4 mm long, while the hairs in E. brunneopilosa are up to 0.75 mm long.

The specimens Tong S.32819 and Gibot SAN 72913 were cited as possibly similar to the putative, and yet to be formally described, taxon ‘ Erycibe sp. A’ in Staples & Syahida-Emiza’s (2015) treatment of the genus in Peninsular Malaysia, but the ovary indumentum (glabrous distally) differs from E. brunneopilosa . Chai S.32133 was initially distributed as Annonaceae and Gibot SAN 72913 was initially determined as Sarcostigma sp. (Icacinaceae) .

Additional specimens examined:— MALAYSIA. Borneo: Sarawak, Bintulu, Segan Forest Reserve [3°04’30.0”N, 113°01’19.8”E], 19 Sep 1972 (fr.), Chai S . 32133 ( CANB, K!, L-digital image!, SAN, SING); Sabah, G . Lumaku, 4°53’ N 115°45’E, 300 m., 6 March 1969 (fl.), Nooteboom 1143 ( K!, KEP!, L-digital image!); Sipitang, 5 miles [8 km] from Kampung Modolong to Kampung Maligan [4°41’15.3”N, 115°42’01.0”E], 7 September 1983 (fr.), Gibot SAN 72913 ( K!, KEP!, L-digital image!, SAR) .

Vernacular:— Iban ( Sarawak): Akar rarak (fide Chai S.32133).

Figures

FIGURE 1. Distribution of Erycibe sangiheensis (star), E.trichocarpa (triangle), E.brunneopilosa (circle).Map made using Simplemappr (https://www.simplemappr.net).

FIGURE 4. Erycibe brunneopilosa Kochaiph. & Utteridge. A Habit, flowering branch B Adaxial surface of lamina and midrib C Abaxial surface of lamina and midrib D Hair, from abaxial surface of leaf E Floral bract F Flower bud G Sepal, abaxial view H Sepal, adaxial view I Corolla and lobules, adaxial view J Corolla showing midpetaline band, abaxial view K Stamen L Ovary and stigma M Fruit N Fruit hair. A–D from Chai S 32133 (K); E–L from Nooteboom 1143 (K); M–N from Gibot SAN 72913 (K). A–K, M–N Drawn by Naoko Yasue; L Drawn by Natthaphong Chitchak.