Durio connatus Priyanti, 2016

Chikmawati, Tatik & Hartana, Alex, 2016, Durio connatus (Malvaceae), a new species from Kalimantan, Indonesia, Phytotaxa 272 (3), pp. 215-219 : 215-218

Durio connatus Priyanti , spec. nov. Fig. 1 & 2

Type:— INDONESIA. Traditional orchard, Batuah village, Kutai Kartanegara Regency, East Kalimantan, 00 o 41.744’ S, 117 o 03.239’ E, 28 January 2012, Priyanti 25 (holotype BO!, isotype WAN!).

Durio connatus is close to D. kutejensis in three characters i.e. leaf shape, fruit shape and aril colour. It can be distinguished from its shorter and wider petals (5 − 6 cm long, 3.6 − 4 cm wide), connate stamens at base and branched from 0.9 − 1.2 cm long into 7 − 8 filaments, petals and stamens caduceus, and fruit easily open on the branch before dropping on the ground.

Tree small to large, 9 − 33 m tall, 67 cm in diameter. Buttress low, rounded. Bark grey, brown, fissured. Petiole 2.8 − 3.5 cm long, 2.6 − 3 mm thick, rather swollen towards apex, densely covered with complex peltate trichomes. Leaf blade coriaceous, oblong, ovate, or obovate-lanceolate, 23.7 − 32 cm long, 8.2 − 12.2 cm wide; base obtuse or acute; apex acuminate, caudate, acumen 1.2 − 2.8 cm long; upper surface glabrous, lower surface covered with dense scales (5 layers); midrib sunken on the upper surface, prominent below, covered with densely complex peltate trichomes. Flower on primary or secondary branches, 5 − 10-flowered cymes; bud oblong, 2.8 − 3 cm long, 1.8 − 2 cm wide, greenish; pedicel cylindrical, densely covered with scales, 4.5 − 4.8 cm long, 3.2 − 3.8 cm in diameter; epicalyx 2-lobed, caduceus, 29 − 33 cm long, 2.1 − 2.5 cm wide; calyx campanulate, 3.8 − 4 cm long, 1.9 − 2.3 cm wide, 4 − toothed, toothed 3 − 6 mm high, 12 − 22 mm wide, outside golden-brown with densely complex peltate trichomes, inside dark brown on the apex, light brown at the base, sparsely covered with simple trichomes; petals pink, 5, broadly spatulate, caduceus, 5 − 6 cm long, 3.6 − 4 cm wide, outside pink, densely covered with cushioned stellate trichomes, inside pink or reddish, glabrous; stamens basally fasciculate in 5 phalanges, pink, caduceus, 27 − 31, filaments densely covered with cushioned stellate trichomes, 3.6 − 4 cm long, branched at 0.9 − 1.2 cm from base; style 1, cream to pinkish, stigma yellow. Fruit oblong, easily opened before dropping to the ground, 20 − 35 cm long, 17 − 29 cm in diameter, pericarp yellowish-green to dark yellow when ripe, stalk 2.5 − 4.2 cm long, 1 − 2 cm in diameter, spines pyramidal and pointed-convex, 1 − 1.4 cm long, sharp. Seed oblong, 2.2 − 3.5 cm long, 1.8 − 2.1 cm wide, testa brown, shiny; aril smooth, yellow to orange, rather juicy to dry, fairly to very sweet, fairly creamy, thin to moderately thick, 3 − 11 mm, completely covering the seeds, aroma like D. zibethinus .

Etymology:—The specific epithet is based on the five stamen phalanges, which are connate to 0.9 − 1.2 cm from the base.

Distribution: — Indonesia: North Kalimantan, East Kalimantan, Central Kalimantan, South Kalimantan, loggedover lowland Dipterocarp forest, valley bottoms, and traditional orchards, between 39 − 200 m above sea level.

Additional specimens examined:— INDONESIA. North Kalimantan, 00 o 00.302’ N, 117 o 42.640’ E, 04 o 00.249’ N 117 o 42.680’ E, 13 July 2012, Priyanti 71, 72 ( BO!) ; East Kalimantan, 0 o 041.744’ S 117 o 03.266’ E, 28

January 2012, Priyanti 24 ( BO!) ; 0 o 041.744’ S 117 o 03.239’ E, 28 January 2012, Priyanti 25 ( BO!) ; 0 o 044.673’ S 117 o 03.428’ E, 23 February 2013, Priyanti 144 ( BO!) ; 0 o 043.573’ S 117 o 03. 332’ E, 23 February 2013, Priyanti 141 ( BO!) ; 0 o 042.336’ S 117 o 03.316’ E, 23 February 2013, Priyanti 146 ( BO!) ; 0 o 044.764’ S 117 o 04.322’, 23 February 2013, Priyanti 150 ( BO!) ; Central Kalimantan, 113 o 56’ E 0 o 43’ S, 24 February 1994, G. Argent 94107 ( BO!) ; South Kalimantan, 02 o 12’40.41” S 115 o 18’5.54” E, 16 September 2012, Priyanti 106 ( BO!) ; 02 o 14’29.4” S 115 o 16’17.6” E, 16 September 2012, Priyanti 113 ( BO!) ; 02 o 14’34.8” S 115 o 16’15.2” E, 16 September 2012, Priyanti 116 ( BO!) ; 03 o 26’9.8” S 114 o 48’14.6” E, 17 September 2012, Priyanti 125 ( BO!), 03 o 26’9.53” S 114 o 48’14.34” E, 17 September 2012, Priyanti 128 ( BO!), 03 o 26’11.32” S 114 o 48’12.71” E, 18 September 2012, Priyanti 134 ( BO!) .

Discussion: Durio connatus is similar to D. kutejensis in several (especially fruit) characters, viz. branch patern, leaf shape, leaf size, petal shape, petal size, petal colour, stamen structure, filament colour, persistence of stamens, ripe fruit shape, pericarp colour, fruit opening, spine structure, aril texture, aril color, and aril taste ( Table 1).

Figures

FIGURE 1. Durio connatus. A. Tree. B. Trunk with spiral branches. C. Stamens and flowers. D. Bud and young fruit on the branch.

FIGURE 2. Durio connatus. A. Habit. B. Flower bud. C. Pistil. D. Outer part of petal. E. Flower. F. Connate stamens. G.Anther. H.Young fruit. I. Ripe fruit. J. Pointed-convex spines. Drawn from holotype Priyanti 25 (BO), by Wahyudi Santoso.