Timonius beamanii K.M.Wong & J.Chen, 2014

Chen, Junhao, Wong, Khoon Meng, Ent, Antony Van Der & Tan, Hugh T. W., 2014, Nine new species of Timonius (Rubiaceae) from Kinabalu Park, Borneo, Phytotaxa 181 (3), pp. 138-150 : 141-143

Timonius beamanii K.M.Wong & J.Chen , sp. nov. ( Figs. 1G , 2A, 2C )

Similar to Timonius borneensis Valeton (1909: 48) ( Figs. 1H , 2B, 2D ), but differing by the fruit shape (globose vs. obovoid), fewer corolla lobes in female flowers (4 or 5 vs. 8–10), pubescence on the lower lamina (appressed hairs mostly as long as co-occurring lanate hairs vs. appressed hairs 2–3× longer than lanate hairs), and fewer flowers per male inflorescence (up to 21 vs. 20–70 flowers).

Type: — BORNEO. Sabah: Kinabalu Park, Mesilau River , 1520 m, 5 February 1964 (♀ plant), Chew & Corner RSNB 4222 (holotype SING; isotypes K, L, SAN) .

Timonius borneensis sensu Beaman & Anderson (2004: 347) , pro parte, non Valeton (1909: 48): quoad Beaman & Perkins 8491, Jusimin 560, RSNB 4143, 4222.

Tree to 21 m tall; trunk to 1.8 m dbh; bark unknown. Stipules triangular, with two lateral ridges converging at the apex, imbricate. Leaves opposite; petioles 1–2.5 cm long, 1.5–2 mm in diam.; blades narrowly elliptic, 6.8–10.4(–13) × 2.1– 3.9(–6.2) cm, base cuneate, apex cuspidate, margins plane, chartaceous, lower surface densely appressed-pubescent on the midrib and secondary veins, with lanate hairs occurring with appressed hairs (mostly as long as the lanate hairs) on the lamina, upper surface plane (not bullate); secondary veins 10–16 on each side of the midrib, 4–8(–14) mm apart from each other; tertiary veins not prominent on lower surface. Inflorescences: female plants with 3–5(–7) flowers per inflorescence, peduncles 0.8–1.3 cm long, peduncular bracts triangular, ca. 4 × ca. 1 mm; male plants with 12–21 flowers per inflorescence, peduncles 0.9–1.8 cm long. Calyx lobes in female flowers 5 or 6, broad-triangular (length about the same as basal width), 1–1.5 mm long, sparsely to densely pubescent outside; in male flowers 5, broadtriangular, ca. 0.5 mm long, sparsely pubescent outside. Corolla in female flowers with tube 4–5 mm long, ca. 3 mm in diam., densely pubescent outside, lobes 4 or 5, broadly ovate, 2–2.5 mm long, densely pubescent outside; in male flowers with tube 5–6 mm long, 2–2.5 mm in diam., densely pubescent outside, lobes 4 or 5, broadly ovate, 2–2.5 mm long, densely pubescent outside. Fruits globose, 7–9 mm in diam., densely appressed-pubescent; peduncles up to 1.8 cm long, sparsely pubescent; persistent calyx lobes broad-triangular, 1–1.5 mm long.

Etymology: —The specific epithet honours Professor John H. Beaman for his research on Kinabalu plants.

Distribution: —Probably endemic to Kinabalu Park.

Habitat: —Lower montane forest.

Proposed conservation status: —The conservation status assessed for T. beamanii using GeoCat was Near Threatened ( IUCN 2001). Although its estimated EOO (35 km 2) satisfies the category of Critically Endangered, there is no evidence of decline or fluctuations in EOO, AOO, number of locations, and number of mature individuals. Furthermore, the known populations are protected within the boundaries of Kinabalu Park (an IUCN Category II National Park), where the habitat is carefully preserved. However, the extreme localisation of its distribution suggests that the known populations may be especially susceptible to stochastic variation in the environment, such as forest fires, droughts and climate change.

Additional specimens examined (paratypes): — BORNEO. Sabah: Kinabalu Park, along road to power station, 1540 m, 28 November 1998 (♂ plant), Rimi et al. SNP 8046 ( SNP); along Timpohon trail, 19 July 2006 (♂ plant), Suzana et al. SAN 148484 ( SAN); Kampung Kiau Nuluh , 5 September 1994 (♂ plant), Jusimin 560 (K, SAN, SNP); Mamut Copper Mine , 1 August 2009 (♀ plant), Dolois SNP 16277 ( SNP); Mesilau River , 27 January 1964 (♂ plant), Chew & Corner RSNB 4143 (K, L, SAN, SING); Pinosuk Plateau, east bank of east Mesilau River , 5 February 1984 (♀ & ♂ plants), Beaman & Perkins 8491 (K), 5 February 1984 (♂ plant), 8491 (L); summit trail, 31 January 2007 (♂ plant), Diwol & Sugawara BORH 158 ( SAN) .

Figures

FIGURE 1. A. Infructescences of Timonius abanii, Sinanggol SAN 47911 (SAN). B. Solitary fruits of T. mutabilis, Aban SAN 56303 (SAN). C. Female inflorescences of T. abanii, Aban SAN 60600 (L). D. Solitary female flowers of T. mutabilis, Aban SAN 64024 (SAN). E. Male inflorescence of T. abanii, Clemens & Clemens 29770 (SING). F. Male inflorescences of T. mutabilis, Mujin SAN 38402 (SAN). G. Infructescences (with most fruits abscised) of T. beamanii, Chew & Corner RSNB 4222 (SING). H. Infructescence of T. borneensis, Wong WKM 3231 (BRUN). Scale bars: 1 cm. [Photos: A, B, D, E, F, and G, J. Chen; C and H, K.M. Wong]

FIGURE 2. A. Female inflorescences of Timonius beamanii, Dolois SNP 16277 (SNP). B. Female inflorescence of T. borneensis, Wong WKM 3231 (BRUN). C. Male inflorescences of T. beamanii, Jusimin 560 (SNP). D. Male inflorescence of T. borneensis, Talib SAN 84768 (SING). E. Leaves of T. bullatus, Chew et al. RSNB 184 (SAN). F. Leaves of T. polyneurus, Teysmann 8361 (K). G. Solitary fruits of T. bullatus, Chew et al. RSNB 184 (SING). H. Infructescences of T. leopoldii, Leopold SAN 89494 (SAN). Scale bars: 1 cm. [Photos: A, C, D, E, and G, J. Chen; B, F, and H, K.M. Wong]