Aeschynanthus rejieae Olimpos & Mansibang, 2021

Olimpos, Shiella Mae B. & Mansibang, Jayson A., 2021, Aeschynanthus rejieae (Gesneriaceae), a new species of lipstick vine from Tawi- Tawi, Philippines, Phytotaxa 487 (1), pp. 83-90 : 84-85

Aeschynanthus rejieae Olimpos & Mansibang , sp. nov. ( Figs. 2 & 3 )

Type:— PHILIPPINES. Tawi-Tawi , Municipality of Panglima Sugala, Barangay Magsagaw, loco dicto Busay , Upper Malum Watershed , 5°7’48.432’’N, 119°56’47.832’’ E, ca. 165 m elev., 3 February 2020, Olimpos 88 (holotype PNH!, isotypes CAHUP!, CEBU!)

Diagnosis: — Aeschynanthus rejieae resembles Bornean species A. obconicus ( Clarke 1883) and Philippine species A. ovatus ( Merrill 1906: 226) Schlechter. (1923: 264) in having ovate leaves and densely hirsute external calyx and corolla. However, A. rejieae can be readily distinguished from A. obconicus in having persistent sparse pubescence on the lamina (vs. few marginal indumentum at margin base), rounded to shallowly cordate leaf base (vs. cuneate to rounded), bluntly acute to obtuse leaf apex (vs. acuminate to acute); fewer flowers per fascicle (2 vs. 1–6), campanulate calyx (vs. broadly cup-shape), densely hirsute internal calyx surface (vs. sparsely pubescent to glabrous); weakly crenate disk (vs. simple annular) and ovary with glandular cilia (vs. with few sessile glands or glabrous).

It differs from A. ovatus in having persistent sparse pubescence on lamina (vs. glabrous), bigger leaves (4.7–7.9 × 2.7–4 cm vs. 1.5–3 × 1.5–2 cm), axillary inflorescence (vs. pseudoterminal or subterminal), fewer flowers per fascicle (2 vs. 5–6), longer pedicels (1–1.8 cm vs. 0.7 cm), campanulate calyx (vs. cylindrical calyx), calyx lobe apex rounded to subtruncate (vs. broad obtuse), internal calyx being hirsute (vs. glabrous) and sparsely glandular ciliate ovary (vs. glabrous ovary).

Description: —Scandent epiphyte with green, slender, long, terete, sparsely pubescent stems, 2.5 mm thick; internodes 6.8–7.5 cm long. Leaves opposite; petioles terete, 3–6 mm long, sparsely pubescent. Lamina ovate, 4.7–7.9 cm long, 2.7–4 cm wide, length/width ratio 2:1, apex bluntly acute-obtuse, base rounded to shallowly cordate, margin entire, venation obscurely 4–5 nerves, with persistent sparse pubescence, coriaceous, adaxial surface green, abaxial surface paler. Inflorescence axillary, fascicle 2-flowered, densely hirsute; peduncles almost obsolete, 3 mm long, 2 mm wide, slightly woody, arising from the axils; bracts oblong-ovate, 4 mm long, densely hirsute and pale green; pedicels 1–1.8 cm long, densely hirsute, pale green. Calyx campanulate, 1–1.7 cm long, not appressed to the corolla, abscission layer at the base, with 5 equal lobes 1.3–1.5 mm long, not spreading; apex rounded to subtruncate and densely covered with hirsute trichomes internally and externally, pale green at the base becoming pink towards lobes. Corolla tubular, inflated at the middle, gently flaring towards the mouth and slightly contracted at the throat, 2.8 cm long, 5–7 mm wide, densely hirsute externally, internally with scattered papillae along the floor of the tube and lateral lobe sinuses, red with cream to yellow bands extending from the middle of the lower 3 lobes to the base; upper lobes erect, oblongelliptic, 5 × 6 mm, apex round; lateral lobes spreading, ovate-elliptic, 5–6 × 4–5 mm, round apex; lower lobe spreading, elliptic, 7 × 4 mm, apex round, lobe margins with glandular cilia. Stamens 4, exerted; staminode ca. 1 mm long; anthers 3–5 mm long, cream white; anterior filaments 1.3 cm long, posterior filaments 1.6 cm long, with sparse glandular cilia on the upper half and papillae at the lower, cream white; pollen light yellow. Disk 1 × 1 mm, weakly crenate, glabrous, white. Pistil 1 cm long; ovary 8 mm long, sparsely glandular ciliate, white; stigma with attachment 1.5 mm long, capitate. Fruit and seed not observed.

Distribution and habitat:—Only known from the type locality in Barangay Magsagaw, Panglima Sugala, Tawi- Tawi, a primary lowland forest at around 135–182 m elevation. The dominant canopy species are Ficus Linnaeus (1753: 1059) spp. , Knema Loureiro (1790: 604) spp. , Myristica Gronov (1755: 141) spp. and Cananga odorata ( Lamarck 1785: 595) Hooker f. & Thomson (1855:130). The understory is composed of Dillenia philippinensis Rolfe (1884: 307) , Polyalthia insignis ( Hooker 1860: 156) Airy-Shaw (1939: 279) , Osmoxylon eminens (Bull 1884: 17) Philipson (1976: 114) , Clerodendrum Linnaeus (1753:637) spp. and Ixora Linnaeus (1753:110) spp. A nearby settlement has left some areas cleared, however, pioneer species of Macaranga Thouars (1806: 26) spp. , Mallotus Loureiro (1790: 635) spp. and Omalanthus spp. Jussieu (1824: 50) were observed.

Conservation status: — Aeschynanthus rejieae was only seen from two individuals hence we cannot conclude if it is a common or rare species. Therefore, we propose it to be listed under the Data Deficient (DD) category.

Etymology:—The species is named after Rejie Sahali-Generale who initiated the biodiversity conservation program in Panglima Sugala, Tawi-Tawi. Through her commitment and political will, she won the support of the local communities for the conservation of the remaining forests and their watershed. Ms. Rejie has taken a strong stand and dedication in conserving and protecting the remaining forests of Panglima Sugala and its unique biodiversity.

Notes: —The type of A.rejieae has relatively small gynoecium indicating early anthesis stage. Since all Aeschynanthus are strongly protandrous ( Middleton 2016), the dimension of its gynoecium might vary in the future collections.

A. rejieae strongly resembles species belonging to the classical grouping that fits under sect. Aeschynanthus . However, Middleton (2016) cautioned the usage of the existing sections. Until now, sectional classification that follows phylogenetic patterns for this genus is subjected for more study.

The intermediate affinity of A.rejieae from both Philippine and Bornean species may suggest an evidence of the transitioning speciation of Aeschynanthus from these ecoregions. Nonetheless, the Philippine species of Aeschynanthus needs phylogenetic and taxonomic attention.

Figures

FIGURE 2. A-H. Aeschynanthus rejieae. A.Axillary inflorescence.B. Top view of flower showing the corolla mouth and lobes.C. Flower D. Longitudinal corolla section E. Longitudinal calyx section showing internal hirsute indumentum and ciliate ovary. F. Filament with glandular cilia (white arrow) G. Leaf H. Leaf base showing the persistent sparse pubescence. Photos by Shiella Mae Olimpos.

FIGURE 3.A-E. Aeschynanthus rejieae illustration.A. Habit with details of leaf indumentum. B. Inflorescence.C. Calyx tube longitudinal section with pistil. D. Corolla (split ventrally). E. Front view showing details of the corolla lobes and stamens. Illustrated by Jayson Mansibang.