rhe Palaeobotalltsf, 26(3): 197-306, 1980. A PETRIFIED LIVISTONA-LIKE PALM STEM, PALMOXYLON LIVISTONOIDES SP. NOV. FROM THE DECCAN INTERTRAPPEAN BEDS OF INDIA U. PRAKASH & K. AMBWANI Birbal Sahni Institute of Palaeobotany, Lucknow-226 007, India ABSTRACT Palmoxyloll livis/ol/oides sp. nov., a fossil IHlm stem showing close affinities with the extant genus Liris/olla is described here from the Deccan Intertrappean beds of Nawargaon in Wardha District, Maharashtra. Key-words - Petrified palm stem, Palmoxylol/, Eocene, Deccan Interlrappean beds (India). ~m ~n:if ~ 'f~ at~~"\qT~Bnit f~f"WOfT-<i~~ ~ 'fiT~ iiHirTlJ;ififOfT-1fTlf'ff~ f~~ro:g<i 01'0 ;jfTo-;ffl11 wmr t!;'l' 'P1IT ~ eM ~, ~ it ~ ifi ~ ~!ft ~1 « ~ om «<fIfR sr;;rrfcr f~f;;wOfT« ~f.r;o e"lICll11Cl I WWCf 'liB <rnrr ~ 'f>T t!;~ ~~ CRT, lfllfTf<rn~Of f~'fw.rr~f:g<i Of ° "IT ° ~T qfUrcr f.fillT iflIT ~ I INTRODUCTION from a neighbouring village Maragour, whereas Palmoxylon intertrappeum Sahni (1964) is known from Sindhi Vihira. ANEWdescl ibedspecieshereofinpetrifieddetail. Thepalmspecimenstem is Recently, a fossil palm leaf axis, Palmocaulon was collected by one of uS (K.A.) costapalmatum, has been described by from the Deccan Intertrappean beds of Kulkarni and Patil (l977b) from Maragsur. Nawargaon Village (21°1'N: 78°35'E) in Palmoxylon livistonoides resembling the ex• Wardha District, Maharashtra. The palm tant wood of Livistona forms an important wood is very well-preserved and shows a contribution to our knowledge of the Deccan lacunar ground tissue towards the centre. Intertrappean flora of Wardha District. It possesses cortical, dermal and subdermal regions together with the roots attached to it indicating a basal region of the stem. MONOCOTYLEDONS So far only little work has been done on the plant fossils of the Deccan Inter• FAMILY - PALMAE trappean SeIies of this region; only three fossil woods are known from Nawargaon. Genus - Palmoxylon Schenk, 1882 Out of these two are palm woods, viz., Palmoxylon nawargaonensis Shukla (1941) Palmoxylon livistonoides sp. novo and P. sclerodermum Slhni (Shukla, 1946) while a dicot wood has been described by . R?ots - Small roots measuring 3-5 mm Kulkarni and Patil (l977a) as Aristolochioxy• In diameter are present outside the cortical Ion prakashii of the family Aristolochiaceae. region (PI. 1, fig. I). They show the Besides, another palm woed Palmoxylon following anatomical characters in transverse deccanense Sahni (1964) has been reported section. 297 298 THE PALAEOHOTANIST Epiblema consists of a limiting layer of flv ratio of the fibrovascular bundles varies somewhat thick-walled, rectangular cells. from 1/1-6/1. The auricular sinus is absent Below this lies hypodermis made up of but the median sinus is concave, sometimes two zones (PI. 1, fig. 5), the outer consisting shallow, and the auricular lobes are usually of 4-5 layers of thin-walled round cells, rounded. Each fibrovascular bundle gene• while the inner part is composed of several rally shows one to two xylem vessels which layers of thick-walled cells with small lumen. are excluded. Radiating parenchyma is ab• The cortex consists of three distinct regions sent in this region but 1-2 layers of tabular (PI. 1, fig. 5; PI. 2, fig. 12). The outer parenchyma are present around the fibrous cortex begins just after the inner hypodermis part of the fibrovascular bundles (Pl. 2 and is composed of a few layers of thin• ~g. ~). Fibrous bundles are rarely see~ walled parenchymatous cells. The middle III thIS zone. Stegmata are present in the cortex comprises loosely arranged lamellate fibrous part of the fibrovascular bundles. parenchymatous cells enclosing air spaces Leaf-trace bundles can be seen in this zone. in this region (PI. 2, fig. 12). These paren• Subdermal Zone - The fibrovascular bun• chymatous cells are mostly circular in shape. dles of this region are bigger in size, The inner cortex also consists of a few sparsely placed 40-60 per cm2 and show layers of vertically flattened parenchymatous regular orientation (PI. 1, figs 3, 4). They cells in which some thick-walled polygonal are circular to oval in shape and measure cells are scattered here and there (Pl. 2, 400 X 600-640 X 800 [Lm in size. The flv fig. 12). The endodermis and pericycle lying ratio varies from 3/1-7/1. The dorsal scleren• below the inner cortex are indistinct. Below chymatous sheath is mostly reniform with this lies the stele of the root. Here at the concave median sinus (PI. 2, fig. 9). The periphery about 14-17 • I '-shaped xylem auricular lobes are generally rounded and arches alternate with the phloem strands the auricular sinus is absent. Generally and lie radially (Pl. 1, fig. 1). These xylem two metaxylem vessels are present in each arches have large metaxylem vessels towards fibrovascular bundle (PI. 2, fig. 9); however, the inner side while smaller proto xylem sometimes one vessel is also seen in a vessels are directed towards the pericycle. few bundles. These are excluded. Tabular Cellular details of the phloem tissue are parenchyma- is present around the fibrous not clear. Pith is composed of slightly part of the fibrovascular bundles in 1-2 lignified cells. layers of cells. The radiating parenchyma Cortical Zone - It is about 1 cm thick is also "present in the bundles associated and consists of numerous fibrous and a with their vascular part. Leaf-trace bundles few fibrovascular bundles scattered in the are-£requ{}1'ltl)LSeen in this n~gion. Stegmata parenchymatous ground tissue (PI. 1, figs are present in the fibrovascular bundles. 1, 6). The fibrous bundles are usually Fibrous bundles are altogether absent. round in shape and measure 100-288 [Lm Phloem is badly preserved but sometimes in size. The fibrovascular bundles are gene• a few cells can be seen represented by rally slightly circular to oval in shape and phloem tissue. measure 150-416 [Lm (PI. 1, fig. 6). They Ground Tissue - The ground tissue of the consist of mostly reniform dorsal scleren• present species is characteristic and shows chymatous sheath and appear to possess a gradual transformation from compact usually 1-2 xylem vessels. The ground nature (PI. 2, fig. 7) in the dermal zone tissue cells are rod-shaped and are mostly to lacunate tissue towards the centre (PI. 2, radially elongated (PI. 1, fig. 6). The fig. 9). In the dermal zone, the ground stegmata are present both in the fibrous tissue is compact, composed of almost and fibrovascular bundles. round to oval as well as rod-shaped paren• Dermal Zone - The fibrovascular bundles chymatous cells which are often tangentially in this zone are closely placed, 130-140 per elongated; these cells are usually restricted cm2 and show regular orientation with xylem between the two fibrovascular bundles (PI. 2, facing towards the centre (PI. 1, fig. 2). fig. 7). However, in the outer part of the They measure 240 x 280-400 x 800 [Lm in size subdermal zone the ground tissue cells and are oval in shape. The dorsal scleren• are usually rod-shaped with small lacunae chymatous sheath is prominent, reniform to appearing at places. Further, going towards complanate in shape (PI. 2, fig. 7). The the centre the ground tissue becomes more PRAKASH & AMBWANI- A PETRIFIED LlV1STONA-LIKE PALM STEM 299 spongy enclosing larger lacunae of irregular figs 9, 10) and measure 400 X 600-640 X 800 shape (PI. 2, fig. 11). The parenchymatous (Lm in the fossil, whereas they are 640 X 720• cells here are composed mainly of rod to 800 X 800 (Lmin the living species. They are often Y-shaped cells. almost regularly oriented in both the species. Leaf-trace Bundles- These are frequently The frequency of the fibrovascular bundles, present throughout the stem but less fre• both in fossil and the living species, quent in the subdermal zone (PI. 1, figs is 40-60 per cmZ and 50-72 per cmz res• 2-4). They are recognized by protruded pectively. The f/v ratio of the fibrovascular tongue-like vascular part with a number of bundles in fossil and living is also the same small vessels. The pitting of the meta• being 3/1-7/1 and the tabular and radiating xylem vessels is scalariform, whereas the parenchyma are present in both. Stegmata protoxylem vessels show annular to spiral are also associated with the fibrous part thickenings. of the fibrovascular bundles. The ground Affinities - The anatomical characters of tissue of this zone in both the fossil and the present fossil palm wood are closely living species is also similar. It consists of comparable with the modern wood of spongy parenchymatous tissue, the lacunae Livistona R.Br. especially with Livistona being bigger towards the centre (PI. 2, chinensis R.Br. in both the dermal and figs 9, 10). The cells are mostly rod-Shaped subdermal regions. This study includes the or oval and rarely Y-shaped enclosing examination of thin sections of a large irregular air spaces. number of palm woods and their published Because of a close resemblance of the descriptions. Amongst the species of Livi• fossil wood with the modern wood of stona examined include stem wood sections Livistona chinensis, which is indigenous to of Livistona rotundifolia Mart., L. australis China and Japan, but cultivated here in Mart., L. chinensis R.Br. and Livistona sp. gardens, it seems quite likely that a somewhat and root wood sections of L. chinensis R.Br. anatomically similar species of Livistona The dermal zone, both in the fossil and the might have been growing in the Deccan living species of Livistona chinensis, is about Trap country during the Eocene times. 1'5 cm thick. The fibrovascular bundles The genus Livistona R.Br.