Lasianthus verticillatus (Lour.) Merr.

Zhu, H., Roos, M. C. & Ridsdale, C. E., 2012, A taxonomic revision of the Malesian species of Lasianthus (Rubiaceae), Blumea 57 (1), pp. 1-102 : 93

128. Lasianthus verticillatus (Lour.) Merr. — Map 9

Lasianthus verticillatus (Lour.) Merr.(1935) 372;H. Zhu (1994) 68; (1998) 156; (2001b) 144; (2002) 90. — Dasus verticillatus Lour. (1790) 142; S. Moore (1925) 250. — Type: Dausus G.48 (holo BM), Vietnam.

Lasianthus sylvestris Blume (1826 –1827) 999; Miq. (1857) 323; (1869) 248; Bakh.f. (1965) 343, syn. nov. — Type: Blume s.n. (holo L, barcode L0057520 ), Java, Rompien .

Lasianthus sylvestris Blume var. subsessilis (Miq.) Miq. (1869) 248. — Lasianthus subsessilis Miq. (1861) 550, syn. nov. — Type: Teysmann 4273 (holo L; iso K), Sumatra, Lampong .

Lasianthus truncatus Bedd. (1874) 2, t. 9; Hook.f. (1880) 189; Deb & M.Gangop. (1991) 302, f. 13. — Type: Beddome s.n. (lecto K, designated by Deb & Gangopadhyay 1991), India, Mahendra Hill.

Lasianthus andamanicus Hook.f. (1880) 189; Deb & M.Gangop. (1991) 276, excl. var. ciliatus Deb & M.Gangop. ; Craib (1934) 207. — Type: Wall. Cat . 8309 (holo K), Andaman.

Lasianthus wrayi King & Gamble (1904) 119; Ridl. (1923a) 162, syn. nov. — Type: Wray 257 (holo K; iso U), Peninsular Malaysia, Perak, 4500 ft.

Lasianthus morus Elmer (1906a) 73; Merr. (1923) 567, syn. nov. — Type: Elmer 7050 (holo A; iso K, NY), Philippines, Palo , Leyte.

Lasianthus tamirensis Pierre ex Pit.(1924) 390. — Type: Pierre 587 (holo P; iso A, K, L, MO, SING), Cambodia, Samrong-tong , Mt Tamire.

Lasianthus nigrocarpus Masam. (1932) 222, nom. nud.

Lasianthus taitoensis Shimizu (1944) 239. — Lasianthus obliquinervis Merr. var. taitoensis (Shimizu) T.S.Liu & J.M.Chao (1964) 145, f. 15; H.J.Li & H.Y.Liu (1998) 293. — Lasianthus verticillatus (Lour.) Merr. var. taitoensis (Shimizu) H. Zhu (1994) 69; (1998) 156. — Type: Suzuki & Fukuyama s.n. (TIU, n.v.), Taiwan.

Lasianthus obliquinervis auct. non Merr.: T.S.Liu & J.M.Chao (1964) 141, f. 13; J.M. Chao (1978) 301; H.J.Li & H.Y.Liu (1998) 293, pl. 132; H.S. Lo (1999) 100, pl. 26: 1–6.

[ Lasianthus chinensis auct. non Benth.: Maxim. (1883) 173;A. Henry (1896) 51; Matsum. (1901) 16; Pit. (1924) 391; H.L. Li (1963) 855, p.p.].

Shrubs, 1.5– 3 m tall; branchlets terete, c. 3 mm diam, appressed-pubescent. Leaves: blades oblong to oblong-lanceolate, 9 –18 by 1.5–7 cm, coriaceous, glabrous above, thinly pubescent beneath, apex cuspidate-acute, acute or cuspidate-acuminate, base acute, midrib and nerves flat or slightly prominent above, conspicuously prominent beneath, nerves 5 – 9 pairs, nervules densely anastomosing, parallel; petioles 5 –10 mm long, pubescent. Stipules triangular, 3–4 mm long, pubescent. Cymes sessile; bracts absent or small subulate bracts; 2 – 5-flowered. Flowers sessile; calyx cupular, 3 –5 mm long, subglabrous or puberulous, tube short, 1–2 mm long, limb 2 –3 mm long, truncate or minutely dentate at apex, puberulous; corolla up to 10–12 mm long, hirsute outside, villous inside, lobes 5, ovate. Drupes subglobose, up to 10 mm diam, crowned by an enlarged cupular and truncate calyx limb, smooth on external surface; pyrenes usually 5, rare 4.

Distribution — India (Andaman and Nicobar Islands), Sri Lanka, Burma, China, Japan (Ryukyu), Vietnam, Laos, Cambodia, Thailand, Malaysia (Peninsular, Sabah), Philippines (Luzon to Palawan and Mindanao), Indonesia (Sumatra, Java, Lesser Sunda Islands, Sulawesi), Papua New Guinea.

Notes — Lasianthus verticillatus is a wide distributed and variable species. It was treated as L. andamanicus and, the form with narrow leaves, as L. truncatus in India and Burma, as L. sylvestris , with the form with narrow leaves as var. subsessilis in Java and Sumatra, as L. tamirensis in Cambodia. It was confused with L. obliquinervis in the Philippines and also confused with L. chinensis and L. trichophlebus in China and Indochina.

Lasianthus verticillatus differs from L. trichophlebus by having more or less appressed pubescence on branches and leaf nerves beneath, stipules usually shorter, c. 3 mm long, flowers usually 5-merous, calyx limb cupular and usually truncate or sometimes minutely toothed, as well as the drupes crowned by a cupular and truncate calyx limb and smooth on external surface.

The specimens from mainland southeast China, Taiwan and Ryukyu that have been treated as L. obliquinervis are clearly conspecific with L. verticillatus . That is why Zhu (1994) reduced L. obliquinervis to a synonym of the latter. After examining specimens indicated as L. obliquinervis from the Philippines in K, L, MO, SING, it is found that these specimens represent more than one Lasianthus species. Even specimens determined as L. obliquinervis by Merrill himself, represent more than one species. Most of them agree well with L. verticillatus , while some do not. When Merrill described L. obliquinervis , he cited 10 collections (syntypes). We have seen only one of them, i.e. Whitford?t 247, isosyntypes in P and US. The isosyntype represents a different species from L. verticillatus . According to Merrill, L. obliquinervis has oblong-ovate c. 5 mm long stipules, calyx limbs with 4–5 triangular lobes and drupes with 6 triquetrous pyrenes and not crowned by an enlarged cupular and truncate limbs, which do not agree with L. verticillatus .

Lasianthus sylvestris , from the type specimen, is the same species as L. verticillatus . Although variety subsessilis has narrower leaves, it is just the same as L. truncatus .

Lasianthus wrayi has branches densely appressed-pubescent; leaves oblong-lanceolate, appressed-pubescent on nerves beneath, nerves 5, nervules parallel; stipules triangular; inflorescences subsessile; calyx campanulate, appressed-hirsute, with 4 small acute teeth. The incomplete duplicate of type specimen in U shows that L. wrayi is very similar to L. verticillatus . None of its characters are beyond the variability of L. verticillatus . It is, therefore, better to sink L. wrayi into L. verticillatus .

The specimens treated as L. morus were mixtures containing L. verticillatus , L. trichophlebus , and L. chlorocarpus . The type specimens of L. morus shows that this species has branchlets sparsely hirsute; leaves lanceolate, subcoriaceous, 10–16 by 1.5 – 2.5 cm, with falcate-caudate apex and acute or cuneate base, glabrous above, thinly appressed-pubescent venation beneath; stipules triangular, c. 2 mm long, hirsute; cymes sessile or very congested; calyx campanulate, pubescent, with a limb truncate or minutely 4-toothed; drupes verrucose, crowned by 4 minute subulate teeth, with 4 pyrenes. This species matches L. verticillatus and is here reduced to the latter.

Lasianthus verticillatus differs from L. chinensis by having usually thinner appressed-pubescent branches and leaf nerves beneath, coriaceous leaves with 5 – 9 pairs of nerves and parallel veinlets, cupulate and usually truncate calyx without teeth or sometime with minute teeth, and the drupes without conspicuous angular.