THE DISTRIBUTION OF THE PODOCARPACEAE. (C. E. Foweraker.) INTRODUCTION: New Zealand possesses seventeen indigenous species of podocarps some of which are classed among the chief timber trees. One species, Dacrydium cupressinum (rimu), may be considered the most important timber tree in the Dominion. According to Hutchinson (1) it forms "65 per cent, of the total timber production, over 40 per cent, of the present visible supply of all timbers and 75 per cent. of the present visible supply of softwoods." This tree is distributed irregularly throughout the Dominion, being found chiefly where the rainfall exceeds 50 inches annu ally. Other notable podocarps of economic value are Dac rydium Colensoi (silver pine), Podocarpus totara (totara), P. spicatus (matai), and P. dacrydioides (kahikatea). The podocarp rain forest of New Zealand presents many interesting and economically important problems; articles in previous numbers of this journal have dealt with the podocarps in various aspects, special attention being paid to rimu in regard to its silvics. No student of New Zealand forestry can fail to be impressed by the part played by the indigenous podocarps, but he may not fully realise that the family of gymnosperms known as the Podocarp aceae is widely distributed throughout the southern hemi sphere. It is the purpose of this paper to deal in a general way with the geographical distribution of the podocarps in the hope that it may be of assistance to students interested in dendrology and in the geographical range of species allied to the indigenous podocarps. I am indebted to Mr. 0. Craddock, M.A., for assistance in the compilation of the map.
NEW ZEALAND PODOCARPS: As stated above the species of podocarps usually as signed to New Zealand are seventeen in number belonging to three genera as follows:— Podocarpus totara (totara). Podocarpus Hallii (Halls totara) Podocarpus acutifolius (sharp-leaved totara) Podocarpus nivalis (alpine totara) 160 Podocarpus ferrugineus (miro) Podocarpus spicatus (matai) Podocarpus dacrydioides (kahikatea) Dacrydium Kirkii (manoao) Dacrydium biforme (pink pine) Dacrydium Bidwillii (Bidwill's pine) Dacrydium cupressinum (rimu) Dacrydium intermedium (mountain pine) Dacrydium Colensoi (silver pine) Dacrydium laxifolium (pigmy pine) Phyllocladus trichomanoides (tanekaha) Phyllocladus glaucus (toatoa) Phyllocladus alpinus (mountain toatoa) The above is the taxonomy adopted by Cheeseman (2), but some of the species, e.g. Podocarpus Hallii, and P. acu tifolius, seem difficult to define and it is probable that regional races of some species occur. It is not the purpose of this paper to deal in detail with the New Zealand podo carps from the point of view of their regional distribution which is somewhat intricate. Two species, viz. Dacrydium Kirkii and Phyllocladus glaucus occur only in the northern part of the Dominion.
GEOGRAPHICAL DISTRIBUTION OF THE VARIOUS GENERA OF THE PODOCARPACEAE. Pilger (3) gives the genera of the podocarps as fol lows :— Pherosphaera (2 spp.) Microcachrys (1 sp.) Saxegothaea (1 sp). Dacrydium (about 20 spp.) Acmopyle (1 sp.) Podocarpus (about 70 spp.) Phyllocladus (7 spp.) The total is therefore seven genera and about one hundred species. It is proposed below to consider in turn the distribution of the species of each genus, the taxonomy followed being that of Pilger. The geographical range of each species is treated generally and broadly. No attempt is made at botanical description as this is beyond the scope of the present paper. (a) PHEROSPHAERA. One of the two species, P. Hookeriana occurs in Tas mania and P. Fitzgeraldii in New South Wales. 161 (b) MICROCACHRYS. One species, M. tetragona in Tasmania. (c) SAXEGOTHAEA. One species S. conspicua in southern Chile. (d) DACRYDIUM. This has a fairly wide distribution with perhaps about 20 species in the Malay Archipelago, New Caledonia, New Zealand, Tasmania and S. Chile. The actual distribution of the majority of the species is as follows:— 1. New Zealand (Already mentioned above.) 2. Tasmania D. Franklini. 3. New Caledonia D. taxoides, D. araucarioides, D. lycopodioides, D. balansae. Jf. Burma, Indo-China, Malay States, Sumatra, Borneo, Philippines, New Guinea, Fiji:— D. elatum. 5. Borneo. D. falciforme, D. Beccarii, and D. Gibbsiae. 6. Chile. D. Fonkii. (e) ACMOPYLE. One species, A. Pancheri in New Caledonia. (f) PODOCARPUS. This genus has the widest distribution of all the podo carps and comprises nearly 70 species distributed as fol lows :— 1. New Zealand . (Already mentioned above.) 2. Australia P. elatus and P. spinulosus (E. Australia), P. Drony- nianus (W. Aust.), P. Ladei (Queensland), P. alpinus (Tasmania and N.S.W.) 3. New Caledonia P. ferruginoides, P. Viellardii, P. ustus, P. minor, P. Muelleri, P. gnidioides. .£. Malay Archipelago, Philippines, New Guinea, Etc. P. amarus (Java, Sumatra; N. Guinea and Queens land), P. Motleyi (Borneo), P. Blumei (Java, Moluccas, 162 UJ < uUJ < •a. < u o Q 0 Q.
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_ N >0 ^- IO O N Celebes, N. Guinea, Philippines), P. polystachyus (Java, Sumatra, Borneo, Philippines), P. Rumphii (N. Guinea, Celebes, Moluccas, Philippines), P. thevetiifolius, P. Schlechteri, P. Ledermannii (New Guinea), P. Pilgeri (Celebes and Philippines), P. costalis, P. philippinensis and P. glaucus (Celebes and Philippines). P. Koordersii (Java). 5. Pacific Islands P. vitiensis (Fiji). 6. Japan P. macrophyllus and P. nagi (Japan), P. nankoensis and P. Nakaii (Formosa). 7. Africa P. falcatus and P. latifolius (S. E. Africa), P. graci- lior (Uganda), P. Manii (San Tome), P. milanjianus and P. usambarensis (E. Africa), P. elongatus (S. Africa), P. madagascariensis (Madagascar). 8. India, Etc. P. neriifolius (Nepal; also in Philippines and New Guinea), P. Wallichianiis (Assam, Burma), P. imbricatus (Burma, also in Borneo, Java and Philippines). 9. South America P. andinus, P. salignus, P. nubigenus (Chile), P. Par- latorei (Argentine and Bolivia), P. oleifolius (Bolivia, Peru, Ecuador), P. glomeratus (Peru, Ecuador), P. Mon tanus (Bolivia), P. utilior (Peru), P. coriaceus and P. raac- rostachyus (Venezuela and Colombia), P. Se?i(n and P. Lambertii (S. Brazil), P. Roraimae (Guiana). 10. West Indies & Central America P. Urbanii and P. Purdieanus (Jamaica), P. angusti folius (Cuba), P. Buchii (Haiti), P. guatemalensis (Guate mala) . (g) PHYLLOCLADUS. The seven species mentioned by Pilger are distributed as follows:— 1. New Zealand P. glaucus, P. trichomanoides, P. alpinus. 2. Tasmania P. aspleniifolius. 3. Borneo P. hypophyllus. 4. New Guinea P. major, P. protractus, (also in Moluccas and Philip pines). 164 REMARKS ON DISTRIBUTION. The above lists of species with references to their geo graphical range will show that the genus with the widest distribution is Podocarpus. This spreads widely embrac ing about 70 species in a wide belt reaching from Africa through Indo-Malaysia, Australia and New Zealand to South America and the West Indies. It is, like the Podo carpaceae as a whole, a genus mainly of the southern hemi sphere but stretches north across the equator in Eastern Africa through Malaysia to India and Japan, and beyond the Andean region into Central America and the West Indies. Dacrydium has a narrower range being found in the Malay Archipelago, Tasmania, New Zealand, the Pacific Islands and Chile. Phyllocladus is still more restricted being confined to the Malay Archipelago, Tasmania and New Zealand. The remaining four genera have but a local distribu tion. Pherosphaera occurs in New South Wales and Tas mania, Microcachrys in Tasmania, Acmopyle in New Cale donia and Saxegothaea in S. Chile. If one assumes the former existence of a southern land mass connecting or comprising the existing southern land masses, one could imagine the existence of some primi tive podocarp "plexus" which gave rise to the existing species after long isolation in their respective habitats. Podocarps do not exist in Europe and North America al though certain alleged fossil forms have been found in various northern countries. It is difficult to speculate on the possible origin of the podocarps, but their wide distrib ution in the southern hemisphere indicates a long evolu tionary phase in these lands. It is worthy of note that the podocarps of New Zea land are all endemic and must have taken a vast period of time to evolve to their present forms. Each New Zealand species has evolved to a type adapted to certain site condi tions. LITERATURE CITED. (1) Hutchinson, F. E. "The Life History of the Westland Rimu Stands." Te Kura Ngahere, Vol. III., No. 2, 1932, p. 53. (2) Cheeseman, T. F. "Manual of the New Zealand Flora," 1925. (3) Pilger, R. "Podocarpaceae," Die Naturlichen Pflanzenfamilien, 13 Band, 1926. 165