REINWARDTIA Published by Herbarium Bogoriense, Kebun Raya Indonesia Volume 5, Part 4, p.p. 371-373 (I960) THE GENUS PITYRANTHE Thw. (Tiliaceae). A. J. G. H. KOSTERMANS * SUMMARY 1. Pityranthe Thw. is incorporated in Diplodiscus Turez. 2. A discussion on the characters of both genera is presented, together with a note, concerning priority. 3. An emendated description of Diplodiscus verrucosus (Thw.) Kosterm., comb. nov. is presented. INTRODUCTION In my paper on Diplodiscus (in Reinwardtia 5: 255—-265, July I960), I hinted to the possibility that Diplodiscus and Pityranthe should be con- generic, but that for lack of the fruit of most species of Diplodiscus, a final decission could not be made. Since the discovery of D. decumbens in fruiting stage and with mature fruit of D. paniculatus at hand, I now feel safe to combine the two genera. Bentham stressed already the close relationship of both genera. K, Schumann enumerated several differential characters, none of which I have been able to corroborate. One of the most important should be the non- confluent anther cells in Pityranthe as opposed to the confluent ones in Diplodiscus. In the specimen Thwaites C. P. 1144 of Pityranthe, the anther cells are confluent in exactly the same way as in Diplodiscus. The fruit of both genera is alike and so are the flower characters. The leaves of Pityranthe verrucosa Thw. have lateral nerves ending in a protruding gland, conspicuous in young leaves; this is nowhere men- tioned. The leaves are usually entire and not crenate as contended by Masters, perhaps this was his way of describing the protruding glands. The number of stamens of Pityranthe is cited as 15 (Thwaites) and 20 (Schumann); in Diplodiscus this figure is slightly higher; the filaments are thinner in Diplodiscus; these differences are certainly not on the generic level. Thanks to the much appreciated help of Mr. L. L. Forman of the Herba- rium, Kew and Mr. Marshall, the Librarian, the following was discovered on the subject of priority. * D. Sc.; Forest Research Institute Bogor; Collaborator Herbarium Bogoriense, Bogor. — 371 — 3 7 2 R E I N W A R D T I A . [VOL. 5 Diplodiscus Turcz. in Bull. Soc. Nat. Moscow 31 (1). — It is stated that permission for printing was given by the Censor on 27th May, 1858. Similar permission for Part 2 was given on 7th September, 1858. There it is most likely that Part 1 was printed by June or July, 1858. Pityranthe Thwaites, Enum. PI. Zeyl. Part (pp. 1—80). — In a letter to Hooker, dated 28th November, 1858, Thwaites thanks Hooker for his letter of 11th October in which Hooker praises the first part of the Enu- meratio. Therefore the Enumeratio may have appeared shortly before 11th October, 1858. Hence Diplodiscus Turcz. is probably (but not certainly) earlier than Pityranthe Thw. DIPLODISCUS Turcz. D i p l o d i s c u s Turcz. in Bull. Soc. Natural. Moscow 31 (1) : 235. June-July 1858; Bentham & Hook, f., Gen. PI. 1: 232. 1862; Walpers Ann. 7: 442. 1868; Baillon, Hist. PL 4: 184. 1872; Pfeiffer, Nomencl. 1 (2): 1096. 1874; Dumont in Adansonia 6: 181. 1887; K. Schumann in Engl. & Prantl, Nat. Pfl. Fam. 3 (6): 17. 1895; Burret in Notizbl. bot. Gart. Berlin 9: 618. 1926. Pityranthe Thwaites, Enum. PI. Zeylan. 29. Oct. 1858; Benth. & Hook., I.e.; Walpers, I.e.; Beddome, Fl. Sylvat. t. 109. 1872; Baillon, I.e.; Pfeiffer, I.e. 2 (1): 735. 1874; Masters in Hook, f., Fl. Brit. Ind. 1: 382. 1874; Dumont, I.e. 182 (Pityranthes); Trimen, Handb. Fl. Ceylon 1: 172. 1893; K. Schumann, I.e.; Burret, I.e. TYPE SPECIMEN — Diplodiscus paniculatus Turcz. DISTRIBUTION. — Ceylon, Malay Peninsula, Philippines, Borneo. Diplodiscus verrucosus (Thw.) Kosterm., comb. nov. Pityranthe verrucosa Thwaites (basionym), Enum. PI. Zeyl. 29. Oct. 1858; Bent- ham & Hook, f., Gen. PI. 1: 232. 1862; Walpers Ann. 7: 442. 1868; Beddome, Fl. Sylvat. t. 109. 1872; Masters in Hook, f., Fl. Brit. Ind. 1: 382. 1874; Trimen, Handb. Fl. Ceylon 1: 172. 1893; Schuman in Engl. & Prantl, Nat. Pfl. Fam. 3 (6) : 17. 1895; Burret in Notizbl. bot. Gart. 9: 618. 1926. — Thwaites C. P. 11U. Small tree; branchlets covered with tiny, non-fimbriate scales, glabres- cent, grey, slightly sulcate. Leaves chartaceous, ovate-elliptical 4—11 by 2—6 cm, acutish to obtuse, base rounded or inconspicuously cordate, margin (in young leaves, at the end of the lateral nerves) gland-bearing, often slightly crenulate in old leaves (concave between two glands), upper surface glabrescent, glossy, smooth, lower surface densely pale brown stellate (hairs slender, horizontal), midrib prominent, nerves 7—8 pairs, straight, erect- patent, running out near margin, lower ones sometimes slightly ascendant; 196#] A. J. G. H. KOSTERMANS: The genus pityranthe 373 secondary nerves lax, prominulous. Petiole 1—1.5 cm long, covered with tiny, non-fimbriate scales, slightly swollen at apex. Panicle terminal, lepidote, up to 18 cm long, many-flowered, branches stiff, bracts caducous. Pedicel 3 mm; calyx urceolate, lepidote, ca 4 mm long, base truncate or saccate; lobes ca 1 mm, erect; petals spathulate, twice as long as calyx; filaments free, rather thick, glabrous, slightly longer than the petals; staminodes ligulate, shorter than the filaments; ovary scaly with a single glabrous style with inconspicuous stigma. The species may be differentiated from the other species of Diplodiscus by the gland-bearing leaves and the thicker filaments. C e y l o n . — Central Province, fl., fr., Thwaites 1144 (BO). img562_Page_1 img562_Page_2 img562_Page_3