Palaquium aulandrum A.Phang, 2025

Phang, Aireen, Middleton, David J & Wilkie, Peter, 2025, TRANSFER OF THE GENUS AULANDRA INTO PALAQUIUM (SAPOTACEAE) AND ASSOCIATED NOMENCLATURAL CHANGES, Edinburgh Journal of Botany 82 (2063), pp. 1-10 : 4-6

Palaquium aulandrum A.Phang , sp. nov. – Type: [ Malaysia], Borneo, Sarawak, Gunung

Balang, Batang-Lupar, Beccari 3347 (holotype FI [ FI008956 ]; isotypes FI [ FI008956 ],

G [G00439184], K [K000777764], L [L0006112], P [P00640328]).

Aulandra beccarii auct. non (Pierre ex Dubard) P.Royen: Royen, Blumea Suppl. 4: 263 (1958), p.p.

Most similar to Palaquium longifolium (H.J. Lam) A.Phang in the cauliflorous inflorescence, but differs in the smaller leaves (170–300 × (50–) 75–95 mm in Palaquium aulandrum , 320–970 × 72–280 mm in P. longifolium ) and fewer secondary veins (9–15 pairs in P. aulandrum , 22–37 pairs in P. longifolium ).

Tree, size unknown. Twigs rugulose to rugose, 2–5 mm in diameter, reddish brown tomentose, glabrescent. Leaves loosely clustered; stipules lanceolate, up to 1.5 mm

long, outer surface reddish brown tomentose, inner surface glabrous, caducous; petiole flat above, 15–35 mm long, thickened and rugose at base, reddish brown tomentose, glabrescent; blade coriaceous, oblong-obovate to elliptic, apex acuminate, base decurrent along petiole, 170–300 × (50–) 75–95 mm, glabrous above and below; midrib slightly raised or prominent above, raised below, secondary veins 9–15 pairs, ascending at an angle of

50° to 60°, straight or slightly curved, diminishing until inconspicuous near blade margins, impressed above, prominent below, tertiary veins, transverse, inconspicuous above, faint below. Inflorescences fascicles, cauliflorous. Flowers borne on vermiform brachyblasts up to 11 mm long; bracts deltate, up to 1.5 mm long, outer surface reddish brown tomentose, inner surface glabrous; pedicels angular, 2–6 mm long, reddish brown tomentose. Sepals

6, outer sepals ovate, 2.5–3 × 2–2.5 mm, outer surface reddish brown tomentose, inner surface glabrous, margins fimbriate, inner sepals elliptic-ovate, slightly smaller than the outer ones, outer surface reddish brown or greyish tomentose, glabrous towards margin, keeled, inner surface glabrous, margins fimbriate. Corolla (in bud only) up to 3 mm long, lobes oblong, c.2.5 × 1 mm, glabrous outside and inside. Stamens 18, in 3 rows, anthers cordate-sagittate, 1–1.5 mm long, acute, acumen bifurcate or emarginate, hirsute; filaments broadly subulate, united, c. 0.3 mm long, glabrous. Ovary conoid, up to 1 mm long, reddish brown tomentose, glabrous at base. Style subulate, c. 2 mm long, with 6 longitudinal grooves, glabrous except for scattered hairs at the apex. Fruit unknown. Seed unknown.

Distribution. Recorded from only a single location: Gunung Balang, Batang-Lupar, in Sarawak, Malaysia.

Habitat and ecology. Although the exact coordinates of the original collection are not known, Batang Lupar is a significant river in Sarawak within Sri Aman Division, with a navigable length of around 105 km (65 miles), through areas of tropical rain forest with some hilly areas with altitudes up to 700 m. Flowering specimens were found in April.

Etymology. The epithet aulandrum is given to reflect the species’ former placement in the genus Aulandra .

Proposed IUCN conservation category. The species is globally assessed as Critically Endangered ( Julia, 2021; as Aulandra beccarii ), being rare and endemic, recorded from only a single location in Sarawak, thus having an extremely restricted area of occurrence (4 km 2) and similarly limited extent of occurrence. Population reduction is estimated to be severe

(> 80%) due to various consequences of deforestation, land use and habitat loss.

Notes. The type of Aulandra beccarii is the collection Teysmann H.P. 5068 (P [P00645625]; Figure 2A ), as this is the only collection mentioned in the protologue of the basionym, Palaquium beccarii Pierre ex Dubard ( Dubard, 1909). However, the specimen in Paris was determined by Lam in 1938 as the distantly related Palaquium dasyphyllum Pierre ex Dubard. With this determination of Teysmann H.P. 5068, it means that Palaquium beccarii is the same species as P. dasyphyllum . Although Palaquium dasyphyllum was based on the illegitimate name Isonandra dasyphylla de Vriese , which is a later homonym of Isonandra dasyphylla Miq., Art. 58.1 of the Shenzhen Code (Turland et al., 2018) means that P. dasyphyllum must be treated as a replacement name with the same type as the illegitimate name. Palaquium dasyphyllum Pierre ex Dubard has hitherto mostly been treated as having the basionym Isonandra dasyphylla De Vriese from 1860, meaning that it would have priority over P. beccarii from 1909. However, as Isonandra dasyphylla De Vriese is illegitimate, Palaquium dasyphyllum and P. beccarii have equal priority from 1909. We here establish the priority of Palaquium dasyphyllum over P. beccarii .

Specimens examined. Known only from the type specimens.

Figures

Figure 2. Specimen images of collections obtained from Muséum national d’Histoire naturelle, Paris (France): A, Teysmann 5068 [P00645625], holotype of Palaquium beccarii (http://coldb. mnhn.fr/catalognumber/mnhn/p/p00645625); B, Beccari 3347 [P00640328] (http://coldb.mnhn.fr/ catalognumber/mnhn/p/p00640328). Images: Muséum national d’Histoire naturelle, Paris (France).