Chassalia macrocarpa 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 : 40

Chassalia macrocarpa T.Y.Yu sp. nov.

urn:lsid:ipni.org:names:77215411-1

Figs 22–23

Diagnosis

Differs from all other Bornean species of Chassalia in having relatively large fruits (10–12 × 10 × 5 mm); differs from other species of Chassalia from Mt Matang in having larger rachis and capitulum bracts, rachis bracts usually round or acuminate with long acumen which covers the flower buds, and in fruits becoming pale yellowish brown when dry.

Etymology

The epithet was chosen because, within Borneo, this species of Chassalia has large fruits (1.2 × 1 × 0.5 cm).

Type

MALAYSIA – Borneo, Sarawak • 1 st Division, Kuching, Matang , Path to Bukit Tanduk ; alt. 750 m; 23 Apr. 1987; Bernard Lee Meng Hock S 54027 ; holotype: K [ K001129715 ]!; isotype: SAN .

Additional material

MALAYSIA – Borneo, Sarawak • 1 st Division, Kuching, Matang , by trail; alt. 450 m; 27 Oct. 1929; M. & J. Clemens 22373; K!, SAR • 28 Oct. 1929; M. & J. Clemens 22373; K!, SAR • alt. 500 m; 31 Jul. 1963; Paul Chai S 18534 ; A, K!, L, SAN, SAR • Feb. 1915; H. N. Ridley s.n.; K !.

Description

Shrub, 1–1.5 m tall, glabrous. Internodes (1–) 1.5–4.5 cm × 3–4 mm, lower internodes terete, upper internode usually drying flattened, canaliculate, broadening at apex. Leaf-blades narrowly elliptic to narrowly lanceolate, 15–24 × 2–5.5 cm, margin entire, apex acute to acuminate, base cuneate; midrib slightly raised above, domatia absent; secondary nerves 12–16 on each side of the midrib, prominent above; tertiary nerves not visible. Petiole very short, canaliculate, usually slightly winged, 10–25 × 1–2 mm. Stipule not sheathing, broadly flabellate, 1–2 × 1–1.5 cm, apex usually broken. Inflorescence a compound cyme, (1–) 1.8–5 cm long; peduncle (0.5–) 1.5–3.5 cm long; Bracts of second internode of rachis and second branches 2, round to elliptic, 1.2 × 1 cm, usually slightly sheathing at base, apex obtuse, sometimes acuminate with acumen 5 mm long, second branches usually very short to absent, bracts of capitulum elliptic, 10–12 × 5–10 mm. Open flowers not seen. Fruits purplish blue when young, blue when ripe, light yellowish brown when dry, obovoid, 10–12 × 10 × 5 mm. Pyrenes plano-convex, dorsal surface convex, with two adjacent parallel longitudinal crests, each 0.3 mm wide, curved, 0.3 mm apart along their length, forming a longitudinal groove from apex to base between the two crests; ventral surface concave, centre slightly elevated, margin with an endocarpal outgrowth 0.5–0.8 mm wide and a groove between the edge of endocarp and endocarpal outgrowth 0.3–0.5 mm wide. Raphal opening at base of the endocarpal outgrowth, round, 0.2–0.3 mm diameter, 0.2–0.3 mm from the edge of the pyrene wall, apex with a bony spine, flabellate, erect, 1.5 × 0.3 × 0.6–0.7 mm. PGS not detected. Seed not seen.

Distribution, habitat

Borneo: Malaysia, Sarawak, 1 st Division, Kuching, Matang. Mixed dipterocarp forest, alt. 450– 750 m.

Figures

Fig. 22. Chassalia macrocarpa T.Y.Yu sp. nov. A. Flowering shoot. B. Infructescence showing dry fruit. C. Pyrene ventral surface. From Bernard Lee Meng Hock S 54027. Drawn by T.Y. Yu.

Fig. 23. Holotype of Chassalia macrocarpa T.Y.Yu sp. nov. (Bernard Lee Meng Hock S 54027).