Vol. I. No. 1. Pp. 78-84 (1959) A CYTO-SYSTEMATIC SURVEY OF BAMBUSEAE I. The Slender Bamboos of Asia and S. America E. K. JANAKI AMMAL Director, Central Botanical Laboratory, Botanical &rvey of India, Allahabad Introduction (5) In the persistence of the trimerous nature in The present distribution of a plant is the result of lodicules and stigmas. causes which have acted.through a long period of time (6) In the long period that often elapses between and over areas of wide extent. Plants now restricted in two flowering seasons. their range are frequently survivals of families or genera once almost cosmopolitan. This conclusion is based on Thus Bamboos may be considered to have those comparative investigation of ancient Floras. The exist- characters of the Gramineae which are considered ence of fossil grass in the Tertiary and possibly Upper 'primitive'. Cretaceous rocks is generally accepted. Remains of The rapidity of evolution in herbaceous species which Arundo and Phragmites have been found in the Ter- produces 50-100 generations in one century is bound tiary rocks of Europe : while satisfactorily preserved, to be greater than in trees where due to long interval vegetative shoot of a Bamboo, Chusquea oxyphylla between two generations, there is an 'evolutionary lag'. comparable with C. cuminii has been described by In bamboos the interval between flowering periods Frenguelli and Parodi (1941) from the Tertiary of El varies in the different tribes, and genera. Contrasting Mirador in Argentina. Thus grasses have a geological with some of the annual flowering slender bamboos of history as distant as any other flowering plant. the Himalayas and the Nilgiris, Bambusa bambus, the To-day grasses are represented in all parts of the common bamboo of South India, flowers gregariously earth's land surfaces where conditions are suitable for once in 10-30 years, while B. polymorpha is reported the growth of flowering plants. to flower only once in 80 years. In Phyllostachys bambu- It was Robert Brown, the discoverer of the cell soides the life cycle is 120 years! We may therefore, find nucleus, who in 1810 classified grasses into the two main that in the Bambuseae we are confronted with a slow sub-families. motion picture of the evolution of grasses as a whole. (1) The Pooideae, having spikelets of one to many The aim of the present study is to see what relationship, flowers, with the spikelet breaking up leaving if any, exists between 'systematic' characters and the the glumes behind, and chromosome picture of the different genera of Bamboos. (2) The Panicoideae, having spikelet of 2 flowers, with the spikelets falling away whole. Classification of Bamboos Though the limits of these sub-divisions have since Munroe (1866) classified Bamboos into three main been very much modified, it marked a stepping stone in sub-divisions: the classification of grasses. Amongst the 600 genera (1) Triglossae or Arundinariinae having 3 stamens and 10,000 species of grasses, the Bamboos in which and 3 lodicules generally. there are 50 genera and 1,000 species, are sufficiently distinct to be placed in a third great, sub-family, the (2) Bambuseae verue or True Bamboos having 6 Bamb~csoideae,as was done by E. G. Camus (1913). stamens and the fruit a caryopsis. Bamboos stand.out from the rest of the grasses (3) Bacciferae or Berry bearing Bamboos with 6 (1) In being woody perennials. or more stamens and the fruit, a berry or nut. (2) In having leaves with a well defined petiole- This classification which has become outdated will be like base that are articulated with the sheath. adhered to for the purpose of this study as it divides (3) In bearing leaves on branches and not directly Bamboos into three well marked morphological types. on the main stem as in other grasses. To the Triglossae of Munroe which included the '8 (4) In the true or primary leaves which arise genera, Arundinaria, Thamnocalamus, Phyllostachys, from the main stem, being converted in 'culm- Arthrostylidum, Aulonemia. Merostachys, Platonia and sheaths' in which the blades are reduced in size Chusqueae, belong the Slender bamboos which form and character until they cease to function as the subject of the present study. true leaves. Hubbard (1934) has grouped these into the three tribes, A CYTO-SYSTEMATIC SURVEY OF BAMBUSEAE Arundinaria anceps Chimonobanibrrsa falcata Cliimonobamh~rsakhasiana 2n=48 x 3000 2n=48 x 3000 2n=48 x 3000 Chusqsrea culeou Phyllostachys flexuosa Phyllostachys nigra var. uncfata 2n=48 . x 3000 2n=48 x 3000 2n=54 x 3800 Pleioblastus bngustifolirrs Pleioblastus viridi-striatirs 2n=48 x 3000 2n=48 x 3000 79 A CYTO-SYSTEMATIC SURVEY OF BAMBUSEAE Snsn veitchii 2n=48 x 3000 A CYTO-SYSTEMATIC SURVEY OF BAMBUSEAE Sinarundinaria nitido 2n=48 x 3000 Arpndinariae, Arthrostylidae, and Chusqueae. The dis- collected from the Nilgiris, Assam, Darjeeling and the tinguishing characters of these tribes are given below: Indian Botanic Gardens, Sibpur, while materials of the Arundinariae stamens 3, rarely 6, with free filaments. Chinese and Japanese and the rare Himalayan bamboos Spikelets 1 to many flowered. Palea usually. 2 heeled. and the S. American Chusquea reported in this survey Pericarp thin, adnate to the grain (Sasa, Oreiostachys, were collected from the Bamboo Gardens of the Royal Chloothumnus, Arundinariae, Thamnocalamus, Far- Botanical Gardens of Kew and Edinburgh. I take this gesia, Phyllostachys, Microcalamus, Glaziophyton). opportunity of thanking the Directors of these Gardens Arthrostylidiae stamens 3, with free filaments. for allowing me to collect material and to Mr. Hubbard Spikelets with imperfect flower at base and summit. of Royal Botanical Gardens, Kew, for their correct Style very deeply bifid. Pericarps thin, adnate to the identifications. It is, however, to be regretted that @sin (Arthrostylidium, Aulonemia, Merostachys). material of the S. American Arthostylidiae was not Chusqueae stamens 3 with free filaments, the flowers available for inclusion in this survey. at the base of the spikelets imperfect. Style short, bifid. Young shoots 1"-2" above ground were stripped of Stigmas 2, very rarely 3, pericarps thin, adnate to the their culm leaves and after splitting lengthwise, were im- grain (Chusqueae, Planotia). mersed in Acetic Alcohol ratio 1: 3. The material was AU the genera belonging to these tribes are com- transferred after 24 hours to 70% alcohol where it may Posed of species of more or less slender nature with be left for years with occasional change of alcohol. culms from t" to 2" in diameter and height seldom Sections were cut with a hand razor from the pith cells exceeding 20 feet. They are found distributed in both the and squashed in lacmoid. The large pith cells will be Eastern and Western Hemisphere specially on hills and found to be actively dividing with metaphase plate8 mountains. The Chusqueae and Arthrostylidiae belong with well spaced chromosomes. All drawings were made to the New world, while the Arundinariae are found in with a Camera lucida using x30 eye piece and oil immer- both Eastern and Western Hemisphere. In the temperate sion x90 giving a magnification of x3000. regions they occur at lower levels. They include the hardly bamboos characteristic of the Himalayas, China Observation and Japan which have found their way as cultivated I have examined in all 55 plants belonging to 50 plants in the gardens of ~uropeand America. species representing 13 of the 15 genera of Nakai and The Arundinaria-Phyllostachys complex of Munroe 3 species of the S. American genus Chusqueae from col- has been re-examined by Nakai (1925) and the group lections received at Kew from Chile and Magellan. split up into 15 genera. According to Nakai the genus The chromosome numbers of the genera studied are Arundinaria grows only in America and in very restrict- given in the table together with their distribution. All ed areas in Asia as the Naga hills of Assam and E. the genera and species examined by me were found to Himalayas. The distinguishing characters of Nakai's 15 have 2n=48 except Phyllostachys nigra var punctata in genera are outlined as an appendix to this paper. which I found 2n= 54. This plant which was labelled as P. flexuosa at Kew, is probably the same clone for Material and Methods which Hunter (1934) reported 2n=54. P. fiexuosa is a Material of Indian species of Slender bamboos was Chinese plant while P. nigra is the famous Kuri Daki, A CYTO-SYSTEMATIC SURVEY OF BAMBUSEAE the black Bamboo of Japan, which is easily identified. 2n=48 in the genera studied. These are marked * in According to Freeman Mitford (1896) P. nigro-punctata the present list. is taller, hardier and more free growing than the type. This is the first time that the Slender bamboos of There are no other characters to differentiate it from the Himalayas, South India and S. America have been P. nigra. The presence of 6 extra chromosomes in this examined cytologically and compared with the Chinese variety may account for its larger size which was accord- and Japanese species. They are found to have the same ingly selected by horticulturists for vegetative pro- chromosome number 2n= 48. pagation. Thus the Triglossae of Munroe is a natural group Hunter has also reported 2n=54 in Arundinaria which has remained cytologically stable in all the wide- pygmaea Kunz (Pleiobastus pygmaeus). The plant I ex- ly different regions of the world where they are found, amined had only 2n=48 chromosomes. The chromo- The position of Sasa in the Arundinarieae is question- some number of Japanese and Chinese bamboos have able only in view of the 6 stamens present in this genus. been reported previously by Uchikawa (1933, 1935), It is probably a True Bamboo which has undergone ex- Yamaura (1933) and Tateoka (1954) who have all found treme reduction in its vegetative parts.