Lanonia calciphila (Beccari) Henderson & Bacon (2011: 888)

Henderson, Andrew & D ựng, Nguy ễn Qu ốc, 2022, A revision of Lanonia (Arecaceae, Coryphoideae, Livistoninae), Phytotaxa 532 (3), pp. 209-245 : 223-224

3. Lanonia calciphila (Beccari) Henderson & Bacon (2011: 888) .

Licuala calciphila Beccari (1910: 216) . Type:— VIETNAM. Tonkin, rive gauche de la rivière Noire a 3 km au-dessus de Phuong-Lam, 2 May 1888, B. Balansa 4361 (holotype P!, isotype FI!) .

Licuala fatua Beccari (1910: 218) . Type :— VIETNAM. Tonkin occidentale, no date, Père Bon 3130 (holotype P n.v., P image!, isotype FI!).

Licuala tonkinensis Beccari (1910: 214) . Type :— VIETNAM. Tonkin occidentale, Vo-xa , Mt. Chua Hac, 5 May 1885, Père Bon 2901 (holotype P n.v., P image!).

Licuala tomentosa Burret (1940: 98) . Type:— VIETNAM. Muong Thon , route du Hanoi a Hoa Binh, 19 November 1935, A. Pételot 5395 (holotype P n.v., isotypes A!, HNU!, NY!) .

Stems 1.6(1.0–2.0) m long, 2.3(2.0–2.8) cm diameter, solitary or clustered. Leaves 14(10–17) per stem; ligules 12.0(8.0–15.0) cm long, soon disintegrating into fibers; sheaths and proximalmost part of petioles with scattered, brown scales; petioles 52.9(22.5–84.0) cm long, 0.2(0.2–0.3) cm wide at the apex; petiole thorns usually poorly developed, brown or black, more or less regularly arranged on proximalmost part of petiole; hastulas raised, triangular, infolded; leaf blades 58.0 cm wide; costas 7.8(6.0–9.8) cm long, narrow, with a pulvinus at the apex abaxially, with the few segments free except the middle pair joined at their bases; segments 6(4–8) per leaf, not mottled, with minute, reddish-brown scales abaxially, with (on dried specimens) straight margins; middle segments 21.8(16.5–25.5) cm long, 7.0(4.8–10.5) cm wide at the apex; apices of middle segments with adaxial splits not much deeper than abaxial ones. Inflorescences 90.0 cm long; prophylls 16.2 cm long; peduncles length not recorded; rachis bracts tubular, splitting apically and laterally, becoming fibrous at the apex, covered with scattered, reddish-brown hairs; rachillae not filiform nor thick and ribbed, densely covered with wooly, much branched, reddish-brown hairs; staminate rachises length not recorded; staminate partial inflorescences 3(2–3), branched to 2–3 orders; staminate rachillae 3(2–4), 9.0(6.0–11.2) cm long, 1.1(1.0–1.3) mm diameter; staminate flowers 2.2(2.0–2.5) mm long; sepals not pedicellate at the base, densely hairy; petals rounded at the apex; stamens with alternately long and short filaments and small, almost square anthers; filaments not elongate; pistillodes divided into 3 sections; pistillate rachises absent; pistillate partial inflorescences 1, branched to 1 order; pistillate rachillae 1, 15.5(10.0–21.0) cm long, 1.8(1.6–2.1) mm diameter; pistillate flowers length and styles not recorded; fruits 8.5(7.2–9.7) mm long, 7.4(7.6–8.1) mm diameter, globose, red, with smooth surfaces; seeds with a curved basal intrusion.

Distribution and habitat:—Northern Vietnam in Hoa Binh, Ninh Binh, Phu To, and Son La provinces in lowland rainforest on limestone soils at 593(200–1,154) m elevation ( Fig. 8 ).

Taxonomic notes:— Specimens determined as preliminary species Lanonia calciphila share a unique combination of qualitative variable states and are therefore recognized as a phylogenetic species. Type specimens of L. fatua , L. tomentosa , and L. tonkinensis share the same combination and are therefore included as synonyms.

Lanonia calciphila is notable for its strongly dimorphic staminate and pistillate inflorescences, spicate pistillate inflorescences, and pistillate flowers with the pistillodes divided into 3 sections. It also has elongate costas with the few segments free except the middle pair joined at their bases and densely hairy staminate sepals.

It may not always be dioecious; as noted by Henderson & Bacon (2011), the isotype of Licuala tomentosa from A has two inflorescences on the same plant; one is spicate and pistillate, the other is branched and staminate.

Figures

FIGURE 8. Distribution maps of L. acaulis, L. batoensis, L. calciphila, and L. centralis.