Chassalia lancifolioides 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 : 33-34

Chassalia lancifolioides T.Y.Yu sp. nov.

urn:lsid:ipni.org:names:77215409-1

Figs 18–19

Diagnosis

Differs from Chassalia lancifolia sp. nov. in having more coriaceous leaves, leaf-blades lanceolate but not oblanceolate; in having a longer peduncle 1–6.5 cm × 1.5–2.5 mm, while C. lancifolia sp. nov. has a long first internode that resembles a peduncle, but a sessile inflorescence (true peduncle more or less

absent); in having the fruit not significantly ridged (0.2–0.3 mm high) compared to C. lancifolia sp. nov.; in the fruit ventral side not as deeply concave as C. lancifolia sp. nov.

Etymology

The epithet reflects the leaf and inflorescence characters that are similar to Chassalia lancifolia sp. nov.

Type

MALAYSIA – Borneo, Sarawak • Kuching, Lundu District, Sematan area ; alt. 20–50 m; 1°47′ N, 109°45′ E; 26 Apr. 1996; John H. Beaman 12027; holotype: K [ K001129714 ]!; isotypes: UNIMAS, IBEC .

Additional material

MALAYSIA – Borneo, Sarawak • Kuching, Santubong, Telok Pasir ; alt. 100 m; 15 Jun. 1964; Banying & Sibat S 21547 ; K!, SAR .

Description

Shrub to small tree, height not stated, but likely to be more than 40 cm tall, glabrous. Internodes short, 1–2.5 cm × 2–4 mm, lower internodes terete, upper internodes drying slightly compressed and shorter. Leaf-blades narrowly lanceolate, 13.5–29 × 1.5–3.5 cm, margin slightly sinuous when dry, a light yellow line visible very near to margin from apex to base; apex acuminate, acumen 1–2 cm, base attenuate, conspicuously decurrent to petioles, midrib slightly raised above, domatia absent; secondary nerves 12–16 on each side of the midrib, prominent above; tertiary nerves not visible. Petiole with a narrow wing on each side, very short, 10–15 × 1–1.5 mm. Stipule triangular to oblong, 5 × 4–5 mm, sometimes when old the chaffy part broken and divided into 2. Inflorescences compound cymes, 2–9.5 cm long. Peduncle longitudinally minutely striate, apex slightly compressed, 1–6.5 cm × 1.5–2.5 mm, rachis and first branches 5–10 × 1–1.5 mm, second internode of rachis and second branches absent or very short, 4–5 × 1.5–2 mm. Bracts of second internode of rachis and second branches 4, elliptic, 5 × 1–2 mm, bracts of capitulum 2, ovate, slightly broader than bracts of partial peduncle, 3–5 × 2–3 mm. Flowers not seen. Hypanthium and calyx tube obovoid, 1.5 × 1–1.5 mm, calyx lobes 1.25 × 0.7–1 mm. Fruits shiny green, prolate, 7 × 5–6 mm, pedicel short, around 1 mm long. Pyrenes plano-convex, compressed, 7 × 6 mm, dorsal surface convex, with two adjacent parallel longitudinal crests, each 0.25 mm wide, 0.15 mm apart along their length, 0.2–0.3 mm high, forming a longitudinal groove from apex to base between the two crests; ventral surface slightly concave, centrally slightly elevated, margin with an endocarpal outgrowth 0.5–0.8 mm wide, with a groove between the edge of endocarp and endocarpal outgrowth 0.25 mm wide. Raphal opening at base of the endocarpal outgrowth, large, round to trullate, 0.5 mm wide or 1.5 mm × 0.5 mm if trullate, 0.3–0.4 mm from the edge of the pyrene wall, apex with a bony spine, spine triangular, erect, 1 × 0.3 mm. PGS not detected. Seed light brown, hemi-ellipsoid, slightly crested at central part of dorsal side, 6 × 0.5 mm, endosperm not detected.

Distribution, habitat

Borneo: Malaysia, Kuching, around Lundu. Kerangas forest, alt. 20– 50 m.

Remarks

The pyrenes of both this species and Chassalia lancifolia sp. nov. can be very easily separated into two parts between the raphal opening and the base of dorsal groove between the two crests.

Figures

Fig. 18. Chassalia lancifolioides T.Y.Yu sp. nov. A. Flowering shoot. B. Infructescence. C. Dry fruit. D. Pyrene ventral surface. From John H. Beaman 12027. Drawn by T.Y. Yu.

Fig. 19. Holotype of Chassalia lancifolioides T.Y.Yu sp. nov. (John H. Beaman 12027).