Brownlowia latifiana R.C.K.Chung, 2017

Chung, R. C. K. & Soepadmo, E., 2017, Brownlowia latifiana (Malvaceae-Brownlowioideae), a new species from Terengganu, Peninsular Malaysia, Phytotaxa 298 (2), pp. 134-146 : 139-140

Brownlowia latifiana R.C.K.Chung , sp. nov. ( Figs. 4−7 )

Type:—PENINSULAR MALAYSIA. Terengganu: Dungun, Jerangau Forest Reserve , buffer zone by the stream of Compartment 95, 65 m altitude, 4°47.80’N, 103°04.55’E, 21 July 2009 (flowers and fruits), Y.C. Chan & C.L. Lim FRI 65055 (holotype KEP [barcode 246218]; isotypes A, K) .

Brownlowia latifiana is closely related to B. argentata and B. tersa in leaf texture, type of indumentum and other flower and fruit characters. However, the former differs from the latter, B. argentata and B. tersa , by its narrowly elliptic leaves (vs. ovate to broadly ovate or lanceolate), glabrous beneath (vs. densely covered with scales), 10−20 pairs lateral veins (vs. 4−10), large transversely ellipsoid fruits (vs. small depressed obovoid), absence of androgynophore (vs. presence and elongated to 6 mm long, 3 mm thick), persistent calyx lobes (vs. absent), and thick fruit stalk (vs. thin stalk). The main morphological differences between these three species are shown in Table 3.

Small tree to 15 m tall, to 10 cm diameter. Bark grey, smooth; inner bark pinkish. Sapwood white. Twigs terete, 4−10 mm diameter, sparsely dentate-lepidote or glabrous, smooth and rugose towards the young twigs, whitish. Stipules caducous, rarely persistent. Leaves spirally arranged, coriaceous, glabrous; blades narrowly elliptic, (13−)25−50(−55) × (2.4−)5−8.5(−10) cm, base subcordate, margin entire, apex acuminate; midrib rounded, prominent below, raised above, glabrous on both sides; lateral veins (10−)18−20 pairs, looping near margin forming conpicuous intramarginal veins, basal pair prominent below, conspicuous above, short, ascending to c. 2 cm of the length of the blade; tertiary veins reticulate, prominent to faint on both sides; petioles 6−10 mm long, 4−5 mm thick, sparsely dentate-lepidote. Inflorescences terminal, panicles of 3−4(−5)-flowered cyme-like unit, 18−22 cm long, 0.3−0.5 cm thick, lax, peduncle and rachis pale yellowish brown, angular, densely stellate-lepidote and dentate-lepidote; bracts and bracteoles caducous, rarely persistent. Flowers bisexual, actinomorphic, pedicellate; buds obovoid or spheroid, 4−6 × 3−5 mm, densely stellate-lepidote and dentate-lepidote; pedicels (1−)2−4(−5) × 1−2 mm, densely stellate-lepidote and dentate-lepidote. Calyx bell-shaped, pale whitish brown, c. 10 mm long; lobes 5, triangular, valvate, erect, 3−4 mm long, apex acute, densely stellate-lepidote and dentate-lepidote outside, glabrous inside. Petals white, spathulate, c. 15 × 5 mm, base gradually tapering, apex emarginate, glabrous on both sides. Androgynophore short, cylindrical, c. 2 mm long, glabrous. Staminodes lanceolate, c. 3 × 1 mm, shorter than filaments of fertile stamens, glabrous. Fertile stamens numerous; filaments arranged in 5 obscure phalanges, slightly connate at base, c. 10 mm long, glabrous; anthers 0.5−0.7 mm in diameter, pollen flattened Tilia - type, oblate, polar axis (23.4−)25.13(−28.6) μm, equatorial axis (39−)42.69(−46.8) μm, P/E ratio = 0.59, average colpus length 11.19 μm, average colpus width 2.24 μm, 3-colpate, sexine ornamentation reticulate. Ovary transversely ellipsoid, c. 2 × 2.5 mm, densely stellate-lepidote and dentate-lepidote, carpels 5, free, each carpel with 2 ovules; style 1, c. 10 mm long, glabrous; stigma punctiform; only one carpel in each flower develop into mature fruit. Infructescences to 18 cm long, densely stellate-lepidote and dentate-lepidote. Fruits woody, transversely ellipsoid, 12−23 × 19−32 mm, 1-locular, base flattened, with a shallow fissure perpendicular to the flattened bottom divides the fruit partially into two halves, surface uneven with small wart-like, sparsely stellate-lepidote and dentate-lepidote or glabrescent; androgynophore absent or not persistent; calyx lobes persistent, reflexed, sparsely stellate-lepidote and dentate-lepidote; stalk (pedicel) 4−6 mm long, c. 5 mm thick, sparsely stellate-lepidote and dentate-lepidote; pericarp 2−6 mm thick. Seeds 1, depressed ellipsoid, 9−17 × 16−26 mm.

Etymology:—This species is named after the current Director-General of Forest Research Institute Malaysia (FRIM), Dato’ Dr Abd. Latif bin Mohmod, for his contributions in securing fund of RM7.6 million for the Project of Safeguarding the Forest Plant Diversity of Peninsular Malaysia under the Ninth Malaysian Plan; successfully in acquiring the ownership of FRIM land area of 544.3 ha from the Selangor State Government in 2007; and in obtaining the recognition for FRIM as the Natural Heritage Site in 2009 and the National Heritage in 2012.

Distribution and habitat:—This species is endemic to Peninsular Malaysia, known from Jerangau Forest Reserve and Sg. Jerangau in Dungun, Terengganu. It occurs in undulating and riverine areas of lowland dipterocarp forest on clay sandy and alluvial soils at about 65 m elevation.

Conservation status:—Critically Endangered B2ab(iii). To date, this species is known only from the type locality and lies below 100 m. Represented by only two collections and these localities do not lie within a Total Protected Area. The Compartment 95 of Jerangau Forest Reserve is classified as production forest and it was logged in 1996 while the Kuala Sg. Jerangau was surrounded by rubber plantations.

Notes:—There are 15 non-peltate leaved Brownlowia species in South and Southeast Asia, namely Brownlowia argentata , B. cuspidata Low ex Pierre , B. elata Roxb. , B. elliptica Ridl. , B. emarginata Pierre , B. glabrata Stapf ex Ridl. , B. grandistipulata Kosterm. , B. kleinhovioidea , B. macrophylla , B. ovalis Kosterm. , B. palustris Kosterm. , B. rubra Kosterm. , B. sarwonoi Kosterm. , B. tabularis Pierre , and B. tersa . This new species differs from these non-peltate leaved Brownlowia species by its narrowly elliptic leaves with short petioles to 10 mm long, glabrous on both sides, lateral veins to 20 pairs with intramarginal veins formed, and large transversely ellipsoid fruits with persistent calyx lobes.

Additional specimens examined (paratype):—PENINSULAR MALAYSIA. Terengganu: Dungun, Kuala Jerangau [Kuala Sg. Jerangau], sea level, 4°50.40’N, 103°12.49’E, 23 July 1997 (flowers), L.E. Teo & W. Emmanuel KL 4797 (K, KEP! [barcodes 76033, 76034], KLU, L, P).

Figures

FIGURE 4. Brownlowia latifiana. A. Flowering leafy twigs. B. Dense dentate-lepidote scales on calyx, inflorescences and flower buds. C. Part of inflorescence.D. Mature flower bud. E. Opened flowers. F. Longitudinal section of mature flower bud. G. Dissected flower with all sepals, petals and stamens removed. H. Dissected flower with all sepals and petals, and also parts of the stamens and staminodes removed. I. Petals, abaxial side (left) and adaxial side (right). J. Stamens, anterior view (left) and posterior view (right). K. Staminodes, abaxial side (left), adaxial side (centre) and side view (right). L. Mature flower showing androgynophore, ovary, style and stigma. M. Stigma. N. Cross section at the centre of ovary. O. Infructescence. P. Fruit, posterior view. Q. Fruit, anterior view. R. Cross section of fruit. S. Longitudinal section of fruit.All drawn from the type. Drawn by Joseph Pao (SAR).

FIGURE 5. Brownlowia latifiana. Geographic distribution map.

FIGURE 6. Brownlowia latifiana. A. Flowering leafy twigs. B. Fruiting leafy twigs. C. Inflorescence with young flower buds (left and centre), opened flower (centre) and mature flower bud (right). D. Inflorescence with opened flowers and mature flower buds. E & F. Infructescences with young fruits.

FIGURE 7. Brownlowia latifiana. A. Leaves glabrous, abaxial view. B. Twigs sparsely dentate-lepidote. C. Petiole sparsely dentatelepidote. D. Inflorescences and flower buds densely stellate-lepidote and dentate-lepidote. E. Tricolpate flattened Tilia-type pollen, polar view. F. Reticulate sexine ornamentation with verrucate mount in the centre of pollen, polar view (A from Y.C. Chan & C.L. Lim FRI 65055; B−F from L.E. Teo & W. Emmanuel KL 4797).