Chassalia lancifolia 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 : 30-33

Chassalia lancifolia T.Y.Yu sp. nov.

urn:lsid:ipni.org:names:77215408-1

Figs 16–17

Diagnosis

Differs from other Kuching species ( C. lancifolioides T.Y.Yu sp. nov. and C. macrocarpa T.Y.Yu sp. nov.) in having oblanceolate leaf-blades (not lanceolate), sessile inflorescences (peduncle inconspicuous), 4 thin bracts subtending the rachis with 2 longer bracts 10–12 × 1–3 mm and 2 shorter bracts 3–5 × 2 mm, small capitular bracts 5–6 × 2–6 mm, long corolla tube 10–18 mm long.

Etymology

Based on the unpublished name given to some specimens of ‘ Cephaelis lancifolius ’ by H.N. Ridley.

Type

MALAYSIA – Borneo, Sarawak • Matang ; Jan. 1915; H. N. Ridley s.n.; holotype: K [ K001129713 ] !.

Additional material

MALAYSIA – Borneo, Sarawak • Kuching ; 16 Apr. 1893; G. D. Haviland 2998; K ! • Munggu Unjam F. R.; 17 Oct. 1958; F. G. Browne 9663; K!, SING ! • Kuching ; 28 Feb. 1893; G. D. Haviland 2997; K !.

Description

Tall herb to small treelet, 0.9 m tall, apparently unbranched, glabrous. Lower internodes terete, upper internodes usually slightly flattened and canaliculate, internodes (1.5)– 3–4.5 cm long. Leaf-blades narrowly elliptic to oblanceolate, 10–22 × 2–4.5 cm, first pair of leaves at apex sometimes bract-like, very narrow, 1–4 cm × 2–6 mm; apex acuminate, acumen 1–2 cm long, base attenuate, conspicuously decurrent to petioles, midrib slightly raised above, domatia absent; secondary nerves 10–16 on each side of the midrib, prominent above; tertiary nerves not visible; margin drying with a continuous light-yellow line from apex to base. Petiole short, compressed, 5–20 × 0.8–2 mm. Stipule triangular to oblong, 5–8 × 3–5 mm, apex usually bilobed, sometimes divided to the base into 2 lobes, each lobe 5–8 × 2–3 mm. Inflorescences 1.5–3.5 cm long, subsessile (true peduncle absent or inconspicuous), basal lateral partial peduncles 2, subequal to the main rachis, (appearing as though three terminal inflorescences), short, usually flattened, 5–12 × 1–1.5 mm; distal partial peduncles absent or short, 0.5–0.8 × 1–1.5 mm; 5–7 × 1–2 mm; bracts of rachis 4, triangular to lanceolate, usually sheathing at base, the 2 longer bracts 10– 12 × 1–3 mm, 2 shorter bracts 3–5 × 2 mm; capitular bracts 8–10, triangular to ovate, 5–6 × 2–6 mm, outer bracts slightly sheathing at base. Flowers sessile, 8–14 in each capitulum, glabrous apart from inside corolla tube. Hypanthium 1.5–2 × 1–1.5 mm, calyx tube absent, lobes 5, broadly triangular, 0.25 × 1 mm. Corolla white, glabrous 1–1.8 cm long in bud, tube slightly broadened at apex, 1 mm wide at base, apex 2.5–3 mm wide, band of hairs 2 mm wide, at base of stamens 2.5–3 mm from mouth of corolla tube, hairs erect, colourless, 0.1–0.2 mm long; corolla lobes 5 triangular, 3 × 1.5 mm. Stamens 3 mm long, slightly concave, base bifurcate, inserted 1 mm from mouth of corolla, 9 mm from base of corolla, filaments very short and broad, 0.2 × 0.2 mm. Style exserted about 2 mm from mouth of corolla, stigma bilobed, lobes orbiculate, 0.7 mm diameter. Disc cylindric, 0.8 × 0.8 mm, apex flat. Fruits sessile, ellipsoid, 8 × 7 × 6 mm, fruit colour in vivo not recorded, calyx persistent, not accrescent, 0.5 × 2 mm, disc persistent, not accrescent, 0.5 × 1.2 mm. Pyrene plano-convex, 7–8 × 5.5–6.5 × 2–3 mm, dorsal surface convex, with two adjacent parallel longitudinal crests, 0.4 mm wide, 0.25 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 1 mm wide, with a groove between the edge of endocarp and endocarpal outgrowth 0.5 mm wide; raphal opening at base of the endocarpal outgrowth, round, 0.4 mm wide, 0.2–0.3 mm from the edge of the pyrene wall, apex with a bony spine, spine triangular, erect, 0.8 × 0.2 mm. PGS not detected. Seed light brown, hemi-ellipsoid, 6 × 0.5 mm, longitudinally slightly crested at midline of dorsal surface, endosperm not detected.

Distribution, habitat

Borneo: Malaysia, Sarawak, Kuching. On undulating, well drained kerangas, alt. 15 m.

Remarks

No PGS was found on the pyrene of this species like other members of the ‘Involucrate group’. However, in this species, the pyrene splits very easily at the base of the dorsal crest close to the raphal opening. The raphal opening of this species is very small.

Figures

Fig. 16. Chassalia lancifolia T.Y.Yu sp. nov. A. Flowering shoot. B. Central branch of inflorescence. C. Longitudinal view of corolla showing stamens, band of hairs, stigma, style and disc. From H.N. Ridley s.n. (K001129713). Drawn by T.Y. Yu.

Fig. 17. Holotype of Chassalia lancifolia T.Y.Yu sp. nov. (H.N. Ridley s.n.; K001129713).