IAWA Bulletin n.s., Vol. 11 (1), 1990: 61-70

RATIANS - STEM ANATOMY AND TAXONOMIC IMPLICATIONS

by

Gudrun Weiner and Walter Liese'" Ordinariat fUr Holzbiologie, Universitat Hamburg, Leuschnerstrasse 91, 2050 Hamburg 80, F. R. G.

Su.mmary Introduction The stem anatomy of 114 species of the , the climbing palms, belong to the 13 genera of the subfamily Calamoi­ subfamily (Uhl & Dransfield deae has been examined and described. Char­ 1987). This subfamily is composed of 22 acters of taxonomic and diagnostic signifi­ genera with more than 650 species. Of these cance are the number of metaxylem vessels 13 are rattan genera which occur in two geo­ and phloem fields in the vascular bundles, graphic regions: West Africa, with 4 genera the type of ground parenchyma, and the tis­ of which three are endemic (, sue arrangement in the cortex. The 13 rattan , , ), and genera can be distinguished on the basis of , the much larger and more these features. important area with ten genera (Fig. 1). Of There is a distinct correlation between these latter genera, nine are present in Penin­ anatomical features and the taxonomical sub­ sular , although the most species­ division of the Calamoideae. Hapaxanthic rich area is (Dransfield 1981). rattans possess one phloem field in the vas­ In both Peninsular Malaysia and Borneo cular bundles, while the pleonanthic rattans rattan is of considerable economic impor­ have two phloem fields. Taxonomic relation­ tance. However, only about 20 species are ships can be strengthened by such anatomical traditionally used in furniture production, a evidence. major commodity, whereas others are said to Key words: Palmae, Calamoideae, rattan, be of poorer quality. stem anatomy, vascular bundles, phloem, This investigation is an attempt to differ­ xylem, parenchymatous tissue, morphol­ entiate the rattan genera on the basis of ana­ ogy, . tomical differences. A further study will deal

~ Distribution of the rattan genera

Fig. l. Distribution of the rattan genera.

'" Dedicated to Prof. Dr. Helmut J. Braun on his 65th birthday.

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Table 1. Investigated material. Results and Discussion Number of General anatomy of rattan species investigated The stem anatomy of the rattans corre­ sponds to the general structure of the mono­ Calamus 44 cotyledons, represented by collateral vascular 1 bundles embedded in ground parenchyma. 6 The stem is covered by an epidermis consist­ 13 ing of a single cell layer (see Fig. 10). The Eremospatha 2 thickness of the cuticle and the form of the 25 epidermal cells vary (Siripatanadilok 1983). Laccosperma 2 The cortex between epidermis and the vas­ 1 cular system consists of parenchyma cells, Oncocalamus 1 fibres and incomplete vascular bundles. The 9 endemic genera from West Africa possess 5 fibre rows below the epidermis (Fig. 11); the 2 Asian genera, however, have fibre strands 3 (Fig. 10). The central cylinder begins with the first Information about the herbarium vouchers fully developed vascular bundles, which is available from the authors. Only specimens form a complete circle in all genera. In the used for illustrations or of species with an inner part of the culm the vascular bundles aberrant anatomy are cited in this paper. are diffusely scattered. The material came from: Australia, China, The vascular bundles consist of the con­ India, , Malaysia, , the ducting tissue, phloem and xylem, and fibres Philippines, Sri Lanka, Taiwan, and which provide structural support (Fig. 2). West Africa. Most of the samples were taken The phloem consists of sieve tubes with from herbaria. For this reason the exact loca­ companion cells. Parthasarathy (1968) re­ tion of within-stem samples is not recorded. corded simple sieve plates in transverse to Some material was collected in the field with oblique end walls for this subfamily with the an adequate record of the sample location. exception of the genera Eremospatha and

Fig. 2. Plectocomia elongata Becc. (FRI 36081). Vascular bundle with one phloem field and one metaxylem vessel, cross section; FS = fibre sheath, PH = phloem field, MX = metaxylem vessel, PX = protoxylem, PS= parenchyma sheath. -,Fig. 3. Myrialepis paradoxa Becc. (FRI 36057). Vascular bundle with one phloem field and two metaxylem vessels, cross section.­ Fig. 4. Plectocomiopsis wrayi Becc. (FRI 36074). Cross section: ground parenchyma type C. - Fig. 5. Plectocomiopsis geminiflora (Griff.) Becc. (FRI 36077). Longitudinal section: ground parenchyma type C. - Fig. 6. Calamus caesius Blume (DRI 36076). Vascular bundle with two phloem fields and one metaxylem vessel, cross section. - Fig. 7. Calamus caesiu Blume. Cross section: ground parenchyma type A. - Fig. 8. Daemonorops angustifolia (Griff.) Mart. (FRI 36056). Cross section: ground parenchyma type B. - Fig. 9. Calamus manan Miq. (FRI 36068). Longitudinal section: ground parenchyma type A and B 'stacks of coins'.

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Laccosperma. In these genera simple or tran­ Noteworthy are also the 'yellow caps', sitional sieve plates occur mixed with very i.e., fibre sclereids at the outer side of the oblique compound ones. In the present study fibre sheath of the first vascular bundles be­ also the Calamus species were found to have low the cortex (Fig. 12). Because of their compound sieve plates in very oblique end striking appearance they have been named walls (Fig. 15). The length of a sieve tube 'yellow caps' by Siripatanadilok (1974). The member varies from one to more than three feature 'yellow cap' is present only in the rnillimetres. genera Korthalsia, Myrialepis, Plectocomia, Regarding the arrangement of the phloem and P lectocomiopsis. two types have to be distinguished: one The parenchyma sheath always covers the phloem field (Fig. 2) or two separate fields metaxylem vessel(s) and the protoxylem tra­ (Fig. 6). Also of interest is the arrangement cheids. Parenchyma cells in direct contact of the sieve tubes within a phloem field with a metaxylem vessel are of elongated rec­ (Figs. 18, 19). tangular fonn with an intensive pitting of the The xylem is composed of metaxylem, cell walls (Fig. 17). The other parenchyma protoxylem and an associated parenchyma cells of this sheath have not such intensive sheath. The metaxylem consists of either one pitting and their fonn is more roundish. (Fig. 2) or two (Fig. 3) vessels. The diam­ The ground tissue consists of isodiametric eter of metaxylem vessels varies from 150- parenchyma cells with simple pits. Three 250-450 ~m. In the genera Pogonotium and fonns can be distinguished in a cross section: Retispatha the metaxylem vessels are much Type A: cells are weakly branched leaving smaller (130-140 ~m) than in the other regular rounded intercellular spaces be­ genera. The vessel perforations are mostly tween them (Fig. 7); simple. Bhat et al. (1988) describes multiple Type B: smaller, rounded cells with irregu­ perforation plates in smaller metaxylem ves­ larly shaped intercellular spaces (Fig. 8); sel elements for Calamus species. These sca­ Type C: cells thin-walled, large and round larifonn perforations have been observed with relatively small intercellular spaces also in some of the other investigated genera. (Fig. 4). The cell walls exhibits oval, half-bordered pits in an opposite arrangement (Fig. 16). When viewed in a longitudinal section types The protoxylem tracheids bear annular or A and B appear like 'stacks of coins' (Fig. 9). helical secondary wall structures. The dia­ Type C shows short and elongated cells ori­ meter of the protoxylem tracheids is 30-80 ented perpendicularly to each other (Fig. 5). Ilm, i. e., much smaller, than that of the meta­ Some other features, e.g. so-called 'ducts', xylem vessels. raphides and silica bodies (Fig. 13) or 'steg­ The phloem and xylem are surrounded by mata' recorded by Tomlinson (1961) appear­ fibre and parenchyma sheaths (Fig. 2). The ed to be present in all genera investigated. size of the fibre sheaths differs between spe­ cies. The fibres are one to three millimetre Structural features of taxonomic significance long, often contain septa and generally have Based on a comprehensive anatomical polylamellar cell walls (Fig. 14) (Parames­ analysis of the 114 species from the 13 gen­ waran & Liese 1985). era, the following parameters were found to

Fig. 10. Ceratolobus subangulatus (Miq.) Becc. (FRI 36064). Cross section: epidermis (EPI) and cortex with fibre strands (arrow). - Fig. 11. Laccosperma secundiflorum O. Kuntze (Dransfield 7253, K). Epidermis and cortex with fibre rows below the epidermis (arrow). - Fig. 12. Korthalsia rigida Blume (FRI 36063). First vascular bundles with the 'yellow caps' (arrow). - Fig. 13. Calospatha scortechinii Becc. (FRI 36070). Si02 body, longitudinal sec­ tion; x 5,000. - Fig. 14. Calamus caesius Blume (FRI 36076). Cross section of vascular fibres exhibiting polylamellate walls; x 3,800.

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Fig. 15. Calamus manan Miq. (FRI36068). Sieve tube with compound sieve plate in very oblique end wall.

Fig. 16. Daemonorops kunstleri Becc. (FRI 36067). Longitudinal section: metaxylem ves­ sel; cell wall exhibits oval, half-bordered pits in opposite arrangement; x 1,500. - Fig. 17. Calospatha scortechinii Becc. (FRI 36070). Longitudinal section: metaxylem vessel with 'contact parenchyma' (arrow); x 650.

be of special taxonomic significance at and Based on these features all 13 genera can be above the genus level: distinguished from each other. The subdivi­ sion of the Calamoideae consists of hapaxan­ 1. Construction of vascular bundles thic and pleonanthic genera, which show a Phloem - one or two fields different flowering behaviour (Uhl & Drans­ - arrangement of sieve tubes field 1987). Metaxylem - one or two vessels Only the hapaxanthic die after flow­ 2. Type of ground parenchyma ering. The flowering behaviour coincides - cross section: Type A with the number of phloem fields in the vas­ TypeB cular bundles. All genera with only one TypeC phloem field are hapaxanthic (with the excep­ - longitudinal section of Type C: pattern tion of Eremospatha), whereas genera with of elongated and short cells two phloem fields (with the exception of 3. Occurrence of 'yellow caps' Korthalsia) belong to the pleonanthic group 4. Arrangement of the cortex (Table 2). - subepidermal fibre ring The genus Korthalsia exhibits a closerstruc­ - arrangement of parenchyma cells tural resemblance to the Calamus IDaemon-

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Table 2. Differentiation of climbing palms based on the structure of vascular bundles.

Construction of vascular Major types of bundle flowering Genera phloem- metaxylem hapaxanthic pleonanthic field vessel I 2 1 2 Laccosperma x x x Plectocomia x x x Plectocomiopsis x x x Plectocomiopsis geminiflora x x x Myrialepis x x x Oncocalamus x x x Eremospatha x x x Korthalsia x x x Daemonrops x x x Calamus x x x Calospatha x x x Ceratolobus x x x Pogonotium x x x Retispatha x x x orops-group than to the hapaxanthic subtribe only one phloem field. Four of the five Plectocomiinae. Anatomically, Korthalsia is Plectocomiopsis species have one metaxylem quite similar to Daemonorops, but has the vessel and ground parenchyma type C. Plec­ 'yellow cap' as an additional feature (Fig. 12). tocomiopsis can be differentiated from Plec­ The species-rich and economically impor­ tocomia in longitudinal sections. While in tant genera Calamus and Daemonorops can Plectocomia the short cells of the parenchyma be distinguished in terms of their ground pa­ form long horizontal rows, those in Plecto­ renchyma. Calamus possesses type A (Fig. comiopsis form short ones. 7), Daemonorops type B (Fig. 8). Anatomi­ The other species, Plectocomiopsis gemi­ cally closely related to these two genera are niflora (Griff.) Becc. (FRI 36077), is an ex­ Calospatha, Ceratolobus, Pogonotium, and ception with two metaxylem vessels and Retispatha. ground parenchyma type C, like the genus Daemonorops and Ceratolobus are both Myrialepis. However, both differ in the ar­ characterised by two phloem fields, one meta­ rangement of their parenchyma cells when xylem vessel and ground parenchyma of viewed in longitudinal section. In Myrialepis type B. These two genera differ, however, in shorter cells are aligned in short horizontal the arrangement of the sieve tubes within the rows, but in Plectocomiopsis geminiflora in phloem fields. Daemonorops has a single short and long rows. row of sieve tubes (Fig. 18), but Ceratolobus According to Uhl and Dransfield (1987) has diffusely arranged sieve tubes (Fig. 19, the genera Myrialepis and Plectocomiopsis arrow). The same differentiation applies for are closely related. Based on the anatomical the genera Calamus and Calospatha, with the structure P. geminiflora appears as the one former having a single row of sieve tubes in Plectocomiopsis species which is structurally the phloem. most similar to Myrialepis. Within the subtribe Plectocomiinae the The anatomical evidence from the investi­ genera Plectocomia, Plectocomiopsis, and gation of numerous species of all rattan gen­ Myrialepis also possess structural similari­ era strengthens the taxonomic lines suggested ties. These three genera are hapaxanthic with by Uhl and Dransfield (1987) (Fig. 20).

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Fig. 18. Daemonorops leptobus (Griff.) Mart. Phloem field: sieve tubes are arranged in a single row (arrow), cross section. - Fig. 19. Ceratolobus laevigatus (Mart.) Becc. Phloem field: sieve tubes diffusely arranged (arrow), cross section.

- Metroxylinae Korthalsia

~ Daemonorops . Pogonotiwn _ Calaminae Ceratolobus Calamus I Calospatha Climbing palms Retispatha subdivision of Myrialepis CALAMOIDEAE Plectocomiopsis geminiflora ~ Plectocomiopsis - Plectocomiinae Plectocomia

- Ancistropbyllinae -1 ~~:::;a~ l - Oncocalaminae Oncocalamus Fig. 20. Relation between the taxonomic groupings of the rattan genera and anatomical differ­ ences.

A relationship between types of vascular of anatomical structures. This expands and bundles and taxonomy exists also for bam­ supports earlier studies (Weiner & Liese 1988; boo (Grosser & Liese 1973; Wu & Wang Liese & Weiner 1989). Essential anatomical 1976; Wen & Chow 1987). features have also been noted by Tomlinson The results demonstrate the possibility to (1961), Siripatanadilok (1974), and Teoh differentiate the 13 rattan genera on the basis (1978), but no differentiation of the rattan

Downloaded from Brill.com10/04/2021 09:22:06AM via free access Weiner & Liese - Stem anatomy of rattans 69 genera was undertaken on the basis of these Refurences features. Tomlinson (1961) noted an ap­ parent structural difference of the vascular Bhat, K.M., C. Renuka & P.K. Thulasidas. bundles of two Calamus species (C. deeratus 1988. Occurrence of multiple perforation Mann & H.Wendl. and C. scipionum Lour.). plates in the vessel elements of Calamus This is not in agreement with our results. All (Lepidocaryoideae). Curro Sci. 57: 1027- Calamus species examined in this study (in­ 1028. cluding the two above) have the same vascu­ Braun, H. 1988. Dynamik des Wasser­ lar bundles, namely two phloem fields and steigens bei Baumen in verschiedenen one metaxylem vessel. Klimazonen. Holz-Zentralblatt 144: 226- Dransfield (personal communication) has 228. suggested that the apparent structural differ­ Ding. Y. & W. Liese. 1990. On the nodal ence cited by Tomlinson is probably due to structure of bamboo. In preparation. incorrect naming of an individual of Plecto­ Dransfield, J. 1979. A manual of the rattans comiopsis sp. as Calamus scipionum in the of the Malay Peninsula. Malayan For. Singapore Botanic Garden. Records No. 29. For. Dept., Ministry of Siripatanadilok (1983) has added the epi­ Primary Industries Malaysia. dermis to the list of significant anatomical Dransfield, J. 1981. The biology of Asiatic features on the b.asis of cell type and cuticle rattans in relation to the rattan trade and thickness. The present study supports Siri­ conservations. In: The biological aspects patanadilok's findings. Further chemical and of rare conservations (H. Synge, SEM investigations are needed to elucidate ed.): 179-186. John Wiley & Sons, Lon­ the exact structure of the rattan epidermis. don. The different types of parenchyma cells Grosser, D. & W. Liese. 1973. Present status within the parenchyma sheath may be of func­ and problems of bamboo classification. J. tional significance. Those in immediate con­ Am. Arbor. 54: 293-308. tact with the metaxylem vessel are more elon­ Liese, W. & G. Weiner. 1989. Anatomical gated and more densely pitted. They may have structures for the identification of rattan. a special function in water transport, like In: Proc. Intern. Rattan Seminar Nov. the vessel-associated cells in dicotyledonous 1987, Chiangmai, Thailand (A.N. Rao, trees (Braun 1988). It is noteworthy that such ed.): 107-115. Isara Vongkaluang, Bang­ 'contact parenchyma' has also been observ­ kok, Fac. Forestry Kasetsart Univ., ed around vessels in bamboo (Ding & Liese Thailand and IDRC. 1990). Parameswaran, N. & W. Liese. 1984. Fibre In summary, the rattan genera can be dif­ wall architecture in the stem of Rotan ferentiated on the basis of their vascular Manau (Calamus Manau). In: Proc. Rat­ bundle types, ground parenchyma and cor­ tan Seminar Oct. 1984, Kuala Lumpur, tex. The similarities and relations derived Malaysia. The Rattan Information Center from these anatomical features correspond (1985): 123-129. well with the taxonomic groupings proposed Parthasarathy, M. V. 1968. Observations on by Uhl and Dransfield (1987). metaphloem in the vegetative parts of palms. Amer. J. Bot. 55: 1140-1168. Siripatanadilok, S. 1974. Anatomical investi­ Acknowledgements gation of Javanese rattan canes as a guide We express our sincere thanks for pro­ to their identification. BIOTROP, Fac. of viding the samples as well as checking the Forestry, Kasetsart Univ., Thailand (un­ corresponding herbarium vouchers to all her­ published). baria involved. Thanks also to Dr. Michael Siripatanadilok, S. 1983. Characteristics of Trockenbrodt for his charitable suggestions, epidermal cells in relation to taxonomy as well as to Dr. Pieter Baas and Dr. John and quality of rattan canes. Rattan Infor­ Dransfield for valuable criticism. mation Center (RIC) 2 (2): 3-4.

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Teoh Woon. 1978. An exploratory ana­ Weiner, G. & W. Liese. 1988. Anatomical tomical survey of some Malayan rattans. structures and differences of rattan genera Dept. Zool., School BioI. Sci., Univ. from Southeast Asia. J. Trop. For. Sci. 1: Malaya (unpublished). 122-132. Tomlinson, P.B. 1961. Anatomy of the Wen, T. & W. Chow. 1987. A study on the II. Palmae. Oxford Uni­ anatomy of vascular bundles of bamboos versity Press, Oxford. from China. Intern. Bamboo Workshop, Uhl, N.W. & J. Dransfield. 1987. Genera Hangzhow, 1985, in IDRC: 230-243. Palmarum. A classification of palms Wu, S. & H. Wang. 1976. Studies on the based on the work of Harold E. Moore, structure of bamboos grown in Taiwan. Jr. Allen Press, L. H. Bailly Hortorium Bull. Nat. Taiwan Univ. 16. and International Palm Society,Lawrence.

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