Diospyros dussaudii Lecomte, Notul. Syst. (Paris) 4: 113. 1928; in Fl. Indo-Chine 3: 954. 1930.

Duangjai, Sutee, Sinbumroong, Aroon, Chalermwong, Porntawat, Suekaew, Padungsak, Khammongkol, Kwanjai, Kiewbang, Wittawat, Rueangruea, Sukid, Thananthaisong, Theerawat & Suddee, Somran, 2021, Updated description of Diospyros dussaudii Lecomte (Ebenaceae), with lectotypification and notes on its distribution, PhytoKeys 184, pp. 67-82 : 67

Diospyros dussaudii Lecomte, Notul. Syst. (Paris) 4: 113. 1928; in Fl. Indo-Chine 3: 954. 1930.

Type.

Laos. reçu le 4 October, 1913, Dussaud 120 (lectotype designated here, P barcode P00721485; isolectotypes P barcode P00721486 and P 02141495). Figs 1 and 3 - 5 .

Tree, 8-15(-20) m tall, up to 20 cm in diameter; trunk straight, without buttresses; outer bark grey, smooth and sparsely lenticellate; inner bark thick, reddish-brown or blackish-brown; sapwood white. Young branches covered with hairs, persistent or later glabrous. Buds covered by bifarious scales, ca. 3.0 cm long, outside densely pubescent. Leaves alternate; petiole 8-9 mm long, with dense short brown hairs; blade subcoriaceous, oblong or elliptic-oblong, 12.0-16.2 × 3.8-5.0 cm, base attenuate to cuneate, apex acute to acuminate; mid-rib prominent and finely pubescent above, glabrous or slightly pubescent or puberulous below; secondary veins 7-10 on each side, grooved above, raised below; glabrous adaxially, glabrous to tomentose abaxially. Male inflorescences fasciculate, axillary or on older branches below the leaves, covered with bifarious scales at base. Male flowers 4-merous; pedicel ca. 1 mm long, pubescent; calyx tubular, with 4 short lobes, rounded at apex, 6.5-8.0 mm long, pubescent outside, glabrous inside; corolla white, salverform, pubescent outside, glabrous inside, tube ca. 8.0 mm long, cylindrical, lobes 4, lanceolate, 10.0 × 3.0- 3.5 mm; stamens 12-16, arranged in 2 series, attached at base of corolla tube; filaments 1-3 mm long, sparsely pubescent; anthers triangular, ca. 1.8 mm long, apex apiculate, dehiscence sublateral. Female inflorescences 1-flowered, in the axils of leaves or on older branches below the leaves. Female flowers 4-merous; sessile or subsessile, pedicel up to ca. 3.0 mm long, bracteate; calyx green, tube ca. 6.0 mm long, pubescent outside, glabrous inside, lobes rounded, ca. 5.0 × 3.0 mm, pubescent outside, glabrous inside; corolla creamy-white to pale yellow, urceolate, tube ca. 9.0 mm long, ca. 7.0 mm in diameter, lobes elliptic, ca. 10.0 × 7.0 mm, pubescent outside, glabrous inside; staminodes 8, attached at the base of corolla tube; ovary globose, pubescent, 8-locular; style 1, ca. 1 mm long, glabrous, stigmas 4. Fruits globose or depressed-globose, covered with dense orange hairs, 3.8-5.0 × 4.0-5.0 cm, apex rounded, shortly apiculate, 8-locular; seeds 3-8 per fruit, light green when immature, turning yellow and orange when ripe; fruiting calyx divided to base, lobes ovate-oblong, spreading, ca. 4.0 × 5.0 mm, pubescent outside, glabrous inside; fruit stalk ca. 5.0 mm long; mesocarp 3.0-4.0 mm thick, cream with brown dots. Seeds ellipsoid to planoconvex, two faces flat and one face convex, glabrous, ca. 4.0 × 5.0 mm, black, endosperm smooth when young, but slightly ruminated when mature.

Additional specimens examined.

Laos. Khammouan: Nam Theun, Kaeng Luang , landing area near waterfall, 17°45'46"N, 105°20'21"E, 555 m alt., 7 November 2005, fr., Newman et al. LAO 833 (E!, L!) . Thailand. Nakhon Phanom Province: Ban Phaeng District, Phu Langka National Park, trail behind park headquarters, 17°59'06.60"N, 104°07'58.20"E, 197 m alt., 14 June 2013, fr., Suddee et al. 4514 (BKF); Ban Phaeng District , Phai Lom , Phu Langka National Park , Tat Pho Waterfall , 26 December 2019, Khammongkol 207 (BKF) . Chumphon Province: Lamae District, 12 December 2014, Sinbumroong 12122014-1 (fr.) (BKF); ibid., 8 May 2020, Sinbumroong 08052020-1 (female fl.) (BKF); Tha Sae District , 10 December 2020, Sinbumroong 10122020-1 (fr.) (BKF) . Surat Thani Province: Tha Chana District, 4 April 2020, Sinbumroong & Suekaew 04042020-1 (fr.) (BKF); Ban Ta Khun District, Ratchaprapa Dam , 12 Sep. 2020, Sinbumroong 12092020-1 (male fl.) (BKF) .

Distribution.

Laos, Thailand (Fig. 5 ).

Ecology.

Scattered along streams in tropical rain forests and dry evergreen forests. The species occurs in the understorey at altitudes of 100-300 m. The canopy of the tropical rainforest in Kaeng Krung National Park, Surat Thani, where the species occurs, is dominated by Anisoptera costata Korth., Artocarpus rigidus Blume, Dipterocarpus gracilis Blume, Dipterocarpus kerrii King, Palaquium impressionervium Ng and Parashorea stellata Kurz. Dacryodes rostrata (Blume) H.J. Lam forms a high sub-canopy with Hopea oblongifolia Dyer, Hydnocarpus castaneus Hook. f. & Thomson, Mesua ferrea L. and Xerospermum noronhianum (Blume) Blume. Understorey species are Barringtonia pauciflora King, Diospyros sumatrana Miq., Hydnocarpus nanus King, Koilodepas longifolium Hook. f. and Microdesmis caseariifolia Planch. ex Hook.

Conservation status.

As the Laotian population remains unknown, we have classified the species as Data Deficient (DD) based on IUCN Red List Criteria ( IUCN 2019).

Phenology.

Flowering May-October, fruiting May-April.

Note.

When mature, specimens from peninsular Thailand exhibit hairy branches, whereas those collected from Phu Langka National Park have glabrous or glabrescent branches. The Laos specimens match those from Phu Langka National Park.

As mentioned in Newman et al. (2007b), duplicates of Laotian specimens were deposited in three other herbaria in Laos, as well as at P. However, we were unable to study the specimens in Laos due to the COVID-19 pandemic. It is unsurprising that only a few specimens were collected from Laos because Laos has a low rate of botanical collection ( Middleton et al. 2019).

GenBank accession no.

Sinbumroong 12122014-1: MZ457089 (rbcL), MZ457093 (atpB), MZ457101 (matK and trnK intron), MZ457097 (ndhF), MZ457105 (trnL intron and trnL - trnF spacer) and MZ457109 (trnS - trnG spacer). Sinbumroong & Suekaew 04042020-1: MZ457090 (rbcL), MZ457094 (atpB), MZ457102 (matK and trnK intron), MZ457098 (ndhF), MZ457106 (trnL intron and trnL - trnF spacer) and MZ457110 (trnS - trnG spacer). Sinbumroong 12092020-1: MZ457091 (rbcL), MZ457095 (atpB), MZ457103 (matK and trnK intron), MZ457099 (ndhF), MZ457107 (trnL intron and trnL - trnF spacer) and MZ457111 (trnS - trnG spacer). Khammongkol 207: MZ457092 (rbcL), MZ457096 (atpB), MZ457104 (matK and trnK intron), MZ457100 (ndhF), MZ457108 (trnL intron and trnL - trnF spacer) and MZ457112 (trnS - trnG spacer).

Figures

Figure 1. Type specimens of D. dussaudii (M. Dussaud 120) deposited at P. A, B lectotype, P 00721485, C isolectotype, P 00721486 and D isolectotype, P 02141495.

Figure 3. Diospyros dussaudii A habit B branch and leaves C trunk and bark C 1 slash of bark D leaf venation, abaxial view E, F male inflorescences G, H female flower I-K immature fruits L, M mature fruits N, O fruit in cross section showing immature seeds (N) and mature seeds (O). Photographs by Aroon Sinbumroong (A-H, J, L-M and O) and Sukid Rueangruea (I, K and N).

Figure 5. Geographic distribution of D. dussaudii. The solid star and star represent newly recorded localities in Thailand and the solid circle and circle represent localities in Laos. The map was created with SimpleMappr (http: // www. simplemappr. net; Shorthouse 2010).