A JOURNAL ON TAXONOMIC BOTANY PLANT SOCIOLOGY AND ECOLOGY REINWARDTIA Editors SOEDARSONO RISWAN MIEN A RIFAI ELIZABETH A. WIDJAJA Published by HERBARIUM BOGORIENSE BALAI PENELITIAN DAN PENGEMBANGAN BOTANI PUSAT PENELITIAN DAN PENGEMBANGAN BIOLOGI — LIPI BOGOR, INDONESIA Reinwardtia Vol. 11, Part 1, 1 - 55 5 February 1992 IO ISSN 0034 - 365 X REINWARDTIA Vol. 11, Part 1, pp. 41 - 51 (1992) DURIO MACRANTHA KOSTERM., SPECIES NOYA (BOMBACACEAE) FROM NORTH SUMATRA A.J.G.H. KOSTERMANS Herbarium Bogoriense, Bogor, Indonesia ABSTRACT An interesting species of Durio from Sumatra is described and illustrated from a living specimen growing in Bogor. ABSTRAK Sebuah jenis Durio dari Sumatra diuraikan dan digambarkan dari tanaman hidup yang ditanam di Bogor. In 1981 I received from Mr. H. Rijksen a young durian plant, which he had collected in the Mt. Leuser National Park in North Sumatra Now, 10 years later the plant has grown to a tree of 10 m high in my private garden in Gad ok near Bogor and in July 1991 it started to come into bloom. The flower bunches appeared on the bare branches; it took 4—6 weeks from the initial bud to the mature flower. The tree flowered profusely and within three months new buds appeared continuously. It proved to be an undescribed species of durian. Durio macrantha Kosterm., spec. nov. Fig. 1—10 Arbor mediocris ramulis minute dense lepidotis, loins aiternantious, concavis, chartaceis oblongis breve acuminatis vel sensim acutis, basi ob- tusis. petiolis gracilibus lepidotis, supra glabra atro-viridia sat obscure minute reticulata, nervo mediano tenuibus impressis, subtus dense minute lepidota nervo mediano valde prominentibus, costis gracilibus sat patentibus, margine non attingentibus, paniculis ramifloris paucifloris dense lepidotis, pedicellis crassis longis, epicaiyx magnis, sepalis 5 in tubum connatis, lobis triangulari- bus acutis, basi conspicue saccatis, phalangis staminibus 5, parte apicalibus fi- lamentorum liberis, petalis 5 liberis albis magnis reflexis, ovario lepidotis, stylus longis, stigmate conspicuis.— TYPUS: Kostermans 30.000 (BO). Tree, 10 m tall, dbh. 20 cm. Bark smooth, grey. Crown pyramidal, lowest branch 1 m above the forest floor, somewhat drooping. Leaves alternate, in one plane, chartaceous, lower side concave, oblong, 5—7.5 x 16—22 cm, gradually acuminate or sub-acuminate, base rounded, above 4 1 42 REINWARDTIA [VOL. H very dark glossy green with minute reticulation, midrib slender, impressed, ribs filiform, prominulous in a groove; below very densely light golden brown lepidote, scales minute, flat with rather irregular margin, midrib stout, strong- ly prominent, ribs 12—15 pairs, rather patent, slender, prominent, arcuate,, not reaching the margin, in between often thinner, shorter parallel ribs, reti- culation dense, minute. Petiole 10—15 mm, slender, slightly thickened api- cally, densely minutely lepidote, somewhat sub-peltate. Flowers on the bare branches, consisting of a short thick main peduncle with few, 2—3 cm long thick branches, each bearing 2—4 flowers. Pedicels stout. 4—5 cm long, gradually thickened apically. Flow,er buds initially depressed globose, apicu- late, becoming globose and ultimately subovoid-globose, completely covered by the dark densely lepidote epicalyx (inside white, glabrous), thin, tearing into 2—3 parts, at anthesis, up to 2—2.6 cm long. Calyx urn-shaped, the 5 sepals connate, apically with 5 triangular, acute, 5—7 mm long broad lobes, lepidote outside, the bases of the sepals widened into large, horizontal pouches, continuing inside the tube by forming 5 bulbous white knobs, ultimately curving down and ending outside the tube into 5 tiny reflexed appendages; the entire tube up to 2 cm long and 1.5 cm in diam. at the base. Petals free, white, glabrous, large (in bud imbricate), consisting of a thick, flat, stiff, wide, clawlike part, gradually widened apically and ending in a strongly reflexed much thinner, spathulate-orbicular apical part, the whole 3—4 cm long, the margin fringed.' Stamens in 5 phalanges of 5—7 stamens each, the filaments fused in their basal half, the free parts 2—3 cm long bearing clumps of one-celled anthers. Ovary oblong, densely minutely lepi- dote, showing a slight longitudinal furrow. Style reddish, glabrous, rather fleshy, up to 5 cm long, surpassing the stamens, cylindrical with conspicuous capitellate stigma. Fruit (Nov. 1991) inmature with numerous very hard and sharp, sub pyramidal thorns, the latter covered by numerous very tiny fimbriate scales. DISTRIBUTION : Mt. Leuser National Park. North Sumatra, described after a cultivated specimen in the private garden of Dr. Kostermans in Gadok near Bogor, Java. PHENOLOGY : Flowers open in the afternoon and drop in pieces during the night. They have no smell and no nectar. Pollinators are perhaps bats and night months. The flowers had always a few black ants. The branch bases are surrounded by a high annulus of tissue, free from the branch, as if they had to push the bark aside when developing. The species is outstanding among the 3 other species so far known by the very large flowers. Cultivated tree in the private garden of Dr. Kostermans in Gadok near Bogor, July, fl, Kostermans 30.000 (A,AAU,BM,BO,G,K,L,NY,P). 1992] A.J.G.H. KOSTERMANS : Durio macrantha Kosterm. Fig. 1. Duria macrantha Kosterm. Photo : L. Anema Branch insertian. Photo : L. Anema 4 4 REINWARDTIA [VOL. 11 Fig. 3 Flower bunches Photo : J.-U. Nieser 1992] A.J.G.H. KOSTERMANS : Durio macrantha Kosterm. Fig. 4. Inflorescence — Photo : L. Anema REINWARDTIA [VOL. 11 Fig. 5 _ Flower (style missing) Photo : J.U. Nieser 1992] A.J.G.H. KOSTERMANS : Durio macrantha Kosterm. 47 Fig. 6 Insertion of petal Photo : J. U. Nieser 48 REINWARDTIA [VOL. 11 Fig. 7 Cross section flower Photo : J.-U. Nieser 1992] AJ.G.H. KOSTERMANS : Durio macrantha Kosterm. 49 Fig. 8 Calyx from below Photo : J.-U. Nieser 50 REINWARDTIA [VOL. 11 Fig. 9 Buds. Photo : J.-U. Nieser Fig. 10 Branch Bhoto : L. Anema 1992] A.J.G.H. KOSTERMANS : Durio macrantha Kosterm. 51 During the long delay in printing this issue of Reinwardtia the type tree in Dr. Kostermans' private garden produced mature fruit They are dark green with big, pyramidal hard spines with, a very sharp tip and covered by a dense layer of microscopical scales. The fruit, of which the largest was 15 x 23 cm, drops unopened at maturity and dehisces slightly after one or two days on the ground. The large yellowish brown seeds are completed surrounded by a white, thick, juicy, fragrant aril, not much different from that oi the common Durio zibethinus. The species is economically important, because the small size of the tree, which makes manipulation of flowers and fruit possible; in D. zibet- hinus, a tree of 20—30 m high, this was almost impossible. Dr. and Mrs de Wilde of the Rijksherbarium, Leiden, during their collecting trips in nothern Sumatra, never saw this tree. We are trying to prevent its extinction by establishing a nursery, we have no experience about germination and viability. Fig. 11. Durio macrantha Kosterm. Fruit from type tree CONTENTS Page ROCHADI ABDULHADI Seed banks in a sub-tropical rain forest 1 ROCHADI ABDULHADI Floristic changes in a sub-tropical rain forest succession 13 A.J.G.H. KOSTERMANS Two remarkable Lindera species (Lauraceae) probably representing an undescribed genus 23 A.J.G.H. KOSTERMANS A new species of Diplodiscus Turcz. (Tiliaceae) related to Brownlowia Roxb 27 N. SASIDHARAN & K. SWARUPANANDAN A new species of Cassine (Celastraceae) from India , 29 A.J.G.H. KOSTERMANS Reinstatement of Pterocarpus echinata Pers. (Leguminosae — Papilionaceae) ., 33 JUMAAT H ADAM & GC. WlLCOCK. A new natural hybrid of Nepenthes from Mt. Kinabalu (Sabah) 35 A.J.G.H. KOSTERMANS Durio macrantha Kosterm. species nova (Bom- bacaceae) from North Sumatra 41 A.J.G.H. KOSTERMANS Salacia acuminatissima Kosterm., spec. nov. (Celastraceae) from Sri Lanka 53 A.J.G.H. KOSTERMANS Identity of Dracontomelum petelotii Tardleu -Blot (Anacard.) 55 Printed by c v. Bina Karya Cover Rein.Vol 11,Part 1, 1-55 Rein. Vol.11, Part 1, 1-55_Page_21a Rein. Vol.11, Part 1, 1-55_Page_29