Chassalia chewii T.Y.Yu, 2021

Yu, Tian Yi, Turner, Ian M. & Cheek, Martin, 2021, Revision of Chassalia (Rubiaceae-Rubioideae-Palicoureeae) in Borneo, with 14 new species, European Journal of Taxonomy 738, pp. 1-60 : 19-22

Chassalia chewii T.Y.Yu sp. nov.

urn:lsid:ipni.org:names:77215405-1

Figs 10–11

Diagnosis

Differs from all other Kinabalu species of Chassalia in having elliptic to ovate leaves, in the first internode of flowering branches usually very short (1.5–4 cm long), in having 3 peduncles, the main rachis with 3 capitula, and in the bracts of the capitulum being so big that usually they cover the flower buds.

Etymology

Named after Chew Wee Lek who was the collector of most specimens of this new species.

Type

MALAYSIA – Borneo , Sabah • Mt Kinabalu, Ulu Langanani, Sungai Mamut ; 6°04′ N, 116°40.44′ E; alt. 4000 ft; 4 Aug. 1961; fl.; W. L. Chew, E. J. H. Corner & A. Stainton 1226; holotype: K [ K001129712 ] !.

Additional material

MALAYSIA – Borneo , Sabah • Mt Kinabalu, Ulu Liwagu and Ulu Mesilau; 6°00′ N, about 116°35′ E; alt. 5000 ft; 6 Sep. 1961; fl.; W.L. Chew, E.J.H. Corner & A. Stainton 2807; K ! • Mt Kinabalu, Ulu Liwagu and Ulu Mesilau; 6°00′ N, about 116°35′ E; alt. 5000 ft; 22 Aug. 1961; fl.; W.L. Chew, E.J.H. Corner & A. tainton 1948; K ! • Mount Kinabalu, Dallas ; 3000 ft; 1 Dec. 1931; fr.; J. & M.S. Clemens 27341; K ! • Mount Kinabalu, Tenompok ; 5000 ft; 12–23 Feb. 1932; fr.; J. & M.S. Clemens 30336; K ! • Mt Kinabalu, Tenompok ; 5000 feet; 19 Feb. 1932; fr.; J & M.S. Clemens 30335; K ! • Mt Kinabalu, Ulu Liwagu and Ulu Mesilau; 6 Sept. 1961; fr.; W.L. Chew, E.J.H. Corner & A. Stainton 2804; K !.

Description

Herb to small treelet, 0.4–0.9 m tall, apparently unbranched, glabrous. Lower internodes terete, 2.5–4.5(–7.5) × 0.3–0.5 cm, upper internodes usually drying flattened, strongly canaliculate, slightly broadened at apex, 1.5–4 cm long, base 2–4 mm wide, apex 3–5 mm wide, flowering internodes sometimes highly reduced, 0.5–1.5 cm long. Leaf-blades ovate to elliptic, 11–16(–21) × 3–6.5 cm, margin entire, apex acute to acuminate, acumen 1–1.5 cm, base cuneate; midrib slightly raised above, domatia absent; secondary nerves 10–12 on each side of the midrib, prominent above; tertiary nerves not visible. Petiole flattened, canaliculate, (1.5–) 2–6.5 cm × 0.8–1.5 mm. Stipule not sheathing, broadly flabellate, 0.5–1.2 × 0.8–1.8 cm, margin entire, apex usually broken. Inflorescences compound cymose, 3.5–5.5 cm long; peduncle very short to absent; first branches slightly flattened distally, 25 × 1 mm; rachis 4–4.5 cm long; second branches of rachis cymose, 15–20 × 1 mm; bracts of second branches 8–10 × 4 mm, exceeding the flowers and fruits. Flowers sessile in terminal clusters. Hypanthium obovoid, glabrous inside and out, 2–3 mm in total; sepals 5, each broadly triangular, 0.5 × 1 mm. Corolla cream white, tube 7–8 mm long, broadening from midway to top, lower part 1.5 mm wide, apex 5 mm wide; lobes triangular, 3.5–4 × 3–4 mm, apex acute or apiculate. Stamens 2.3–2.5 mm long, with short spur 0.2 mm long; filaments flat and short, mostly hidden under anthers, 0.2–0.3 mm long. Style 7–8 mm long, slightly exserted out of corolla tube; stigma flat and large, 1.5 × 3–3.5 mm, bilobed, with a slightly raised margin less than 0.5 mm long, centre slightly hollowed. Disc conspicuous, cylindrical with a flat top, 0.5 × 1 mm. Fruit green maturing blue, deep brown when dry, ovoid to ellipsoid, 5–6 × 4–5 mm, junction between the two pyrenes slightly grooved, calyx persistent, lobes 5, 0.2 × 0.5 mm. Pyrenes plano-convex, dorsal surface convex, with two adjacent parallel longitudinal crests, each 0.2– 0.3 mm wide, curved, 0.4–0.5 mm apart along their length, forming a longitudinal groove from apex to base between the two crests; ventral surface concave, central part slightly elevated, margin with an endocarpal outgrowth 0.8–1.0 mm wide, with a groove between the edge of endocarp and endocarpal outgrowth 0.2–0.4 mm wide. Raphal opening at base of the endocarpal outgrowth, round, 0.2 mm long, 0.2–0.3 mm from the edge of the pyrene wall, apex with a bony spine, spine triangular, erect, 0.8–1 × 0.2 mm. PGS not detected. Seed brown, hemi-ellipsoid, slightly crested at central part of dorsal side, 0.5 × 4 mm, endosperm at central part of the seed, 0.2–0.3 mm wide.

Distribution, habitat

Borneo: Malaysia, Sabah, around Mount Kinabalu. Lower montane forest, alt. 900–1500 m.

Figures

Fig. 10. Chassalia chewii T.Y.Yu sp. nov. A. Flowering shoot. B. Inflorescence showing capitulum, bracts and flowers. C. Longitudinal view of flower showing stamens, band of hairs, stigma, style, disc, calyx and hypanthium. D. Infructescences. E. Leaf showing another shape of leaf-blade. F. Dry fruit. G. Pyrene ventral surface. H. Pyrene transection. A–C from W.L. Chew, E.J.H. Corner & A. Stainton 1226; D–H from J & M.S. Clemens 30335. Drawn by T.Y. Yu.

Fig. 11. Holotype of Chassalia chewii T.Y.Yu sp. nov. (W.L. Chew, E.J.H. Corner & A. Stainton 1226).