植物研究雑誌 J. J. Jpn. Bo t. 68: 68: 17 0- 173 (1 993)

Seed Seed Coat and Pericarp Anatomy in Some ()

Arun K. PANDEY and Anupama JHA

Department Department of Botany ，Bhagalpur University ，

Bhagalpur ，812007 悶 DIA

ヒマワリ亜連(キク科)数種の種皮の構造

パンディ A. K. ，ジャー A.

パガルプール大学植物学部

(Received (Received on August 31 ， 1992)

Mature Mature pericarp of ， ， ， ， and of consists five five distinct zones: epidermis ，hypoderrnis ，phytomelanin layer ，fibre zone and parenchymatous zone.

In In ， and Zexmenia pericarp is differentiated into four zones and the inner most

parenchymatous parenchymatous zone is absen t. Epiderrnal cells of the seed coat show fibrous thickenings in Encelia ， Enceliopsis ， Verbesina and Zexmenia. Present study suggests placement of Lagascea in subtribe Ecliptinae and and placement of Encelia and Enceliopsis in subtribe Helianthinae.

Subtribal Subtribal grouping of taxa within Heliantheae Helianthinae and Verbesininae and (ii) comment on has received considerable attention of several the systematic position of taxa grouped in the systematists. systematists. Hoffmann (1 890) recognised 11 sub- above subtribes. tribes tribes within Heliantheae. Stuessy (1977) added four four new subtribes. Robinson (1 981) ，however ， Materials and methods recognised recognised 35 subtribes within tribe Heliantheae. Materials for the present study were obtained In In Hoffmann' s (1 890) cI assification of Helian- from seed herbarium of the National Botanical theae ， subtribe Helianthinae was the largest sub- Research Institute ，Lucknow and Herbarium of the tribe tribe with about 82 genera. Stuessy (1977) divided Ohio State University ，Columbus (Table 1). subtribe subtribe Helianthinae into three subtribes; Eclip- Mature achenes were kept in 70% ethyl alcohol for tinae ，Helianthinae and Verbesinae. Robinson a week. Customary methods of dehydration in (1 981) ，on the other hand ， sub-divided Hoffmann's tertiary-butyl-alcohol series and embedding in Helianthinae Helianthinae in only two subtribes; Helianthinae paraffin wax were followed. Microtome sections ， and Ecliptinae. cut between 16 ー22μm thickness ，were stained in The objectives of the present paper are to: (i) safranin- fast green combination. Mature seed coat ， describe describe achene anatomy in members of subtribes dissected out from the mature achenes ，were

-170 ー June June 1993 Joumal of Japanese Botany Vo l. 68 No. 3 171

Table Table 1. Taxa and Vouchers. and Viguiera on the other hand ， the mature pericarp pericarp is distinguishable into five distinct zones ， Lagascea Lagascea mollis Cav. Amita 1538 epidermis ，hypodermis ， phytomelanin layer ， fibre Verbesina Verbesina alternifolia (L.) Britt Landy 739 zone and parenchymatous zone (Figs. 2，3 ，4). The V. V. nelidae Cabrera Cabrera 13005 epidermis is single-layered followed by hypodermal cells. cells. The number of hypodermal cell-layers ， Zexmenia Zexmenia hispida (H.B. K.) Stuessy 105 A. Gray however ，varies. In Encelia ，Enceliopsis ，Lagascea ， Simsia ，Viguiera ， Tithonia and Zexmenia it is arnotii Z. arnotii (Baker) Hassler Bolcke 128 single single layered ， while in Verbesina hypodermis is Enceliafarinosa Enceliafarinosa Gray Mahler & Thieret 5439 3-4 layers thick (Table 2). In Helianthus the E.frutescence E.frutescence Gray Mehill & Lehta 10683 hypodermal zone is 6- 8 layers thick (Fig. 2). The (OS) (OS) cells cells of hypodermis are radially elongated. The Enceliopsis Keill0843 characteristic phytomelanin layer is present just (A. (A. Gray) A. Nels. below the hypodermal zone in all the genera. The Helianthus Helianthus annus Li nnaeus Burkart 23574 phytomelanin-layer is continuous in Encelia ， Enceliopsis ，Verbesina ，Zexmenia and Lagascea decapetalus H. decapetalus L. Pandey 1125 (Figs. (Figs. 1，4 ， 5) but is discontinuous in Helianthus ， Simsia Simsia ghiesbreghtii Spooner & Dorando Simsia ，Tithonia and Viguiera due to presence of (A. (A. Gray) S.F. Blake 2675

uni- or bi 聞 seriately arranged ray-like parenchy- fruticulosa S. fruticulosa Spooner & Guerara matous trabeculae (Figs. 2， 3). Phytomelanin layer (Sprenge l) S.F. Blake 2923 is is underlain by fibre zone which is in the form of S. S. molinae Spooner & Dorado fibre fibre bundles in Simsia ，Viguiera ， Tithonia and Robinson Robinson et R. D. Brettell 2701 Helianthus. Helianthus. Each fibre-bundle is 3--4 -1ayers thick S. S. tenuis (Femald) Spooner & Villasenor in in Simsi αand Viguiera and 6-8-1ayers thick in S.F. S.F. Blake 2550 Helianthus Helianthus and Tithonia. In Encelia ，Enceliopsis ， Tithonia Tithonia tuba ザ'o rmis (Ja じq.) Pandey 1170 Lagasce α， Verbesina and Zexmenia the fibre zone Cass Cass is is continuous and 2-3-1ayers thick. The parenchy- Tithonia (Mill.) Arenas 1152 matous zone is present only in Encelia ，Enceliop- Blake Blake sis ，Helianthus ，Simsia ， Tithonia and Viguiera Viguiera Viguiera guaranitic αChodati Arenas 1153 (Table 2). It consists of 1-4-1ayers of loosely arranged arranged parenchymatous cells. Seed coat: The seed coat in all the presently studied studied studied for thickening pattem. genera is 1-2 cell-layers thick. In Verbesina ，Zex- menia menia (Fig. 5) ， Encelia and Enceliopsis the epider- Observations mal cells of seed coat show fibrous thickenings. Pericarp: Pericarp: In Lagascea ， Verbesina and Zexmenia Such thickenings are absent in Simsia ，Viguiera ， the the mature pericarp is distinguishable into four Tithonia ，Helianthus and Lag α scea (Figs. 1 ，3). distinct distinct zones: epidermis ， hypodermis ， phytomelanin phytomelanin layer and fibre zone (Figs. 1， 5). In Discussion Encelia ，Enceliopsis ，Helianthus ，Simsia ，Tithonia Stuessy (1 977) placed Lagascea ， Verbesina and 172 172 植物研究雑誌第68 巻第3 号 平成 5 年 6 月

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f z-

''''htl1j 司.，「4 げ :-:;!'a寸む :::21 目 !・'ld''d ;・J JIF--‘」 Fd 、回 ， 」司L 5 占目 5 2 ・・・ 吋 一 田 nu〉圃m 0.05 mm. I

Figs. Figs. 1-5: Achene anatomy of some genera of Heliantheae. l. Lagascea mollis. 2. Helianthus decapetalus. decapetalus. 3. Simsia tenuis. 4. Encelia frutescence. 5. Zexmenia hispida. ep: epidermis ， hy: hy: hypodermis ，向: fibre bundle ，fz: fibre zone ， p: phytomelanin layer ， pz: parenchymatous zone ，sc: seed coa t.

Zexmenia together in subtribe Verbesininae but Ecliptinae together with Eclipta and and Robinson (1981) dismantled subtribe Verbesininae Lagascea in subtribe Helianthinae. and placed Verhesina and Zexmenia in subtribe Present observations support placement of June June 1993 Joumal of Japanese Botany Vo l. 68 No. 3 173

Table Table 2. Comparison of pericarp and seed coat anatomy.

品∞巾何1ti) Taxa Taxa Hypodermis Pericarp Parenchy- 郎副pn matous matous LH l .， P vdt:ωu2vd氾 mu n n &・・・h n 0bC3 (No. (No. of layers) Fibrous zone aA 一 0「 zone

A Verbesina Verbesina 『 con t. con t. + 'I'I111ititi--一 Lagascea Lagascea con t. con t. +++ Zexmenia Zexmenia con t. con t. ++++++ Encelia Encelia con t. con t. Enceliopsis Enceliopsis con t. con t. Simsia Simsia discon t. discon t. Viguiera Viguiera discon t. discon t. Tithonia Tithonia discon t. discon t. 正 oo Helianthus Helianthus U discon t. discon t.

con t.: continuous ，discon t.: discontinuous ， +: present ，一: absen t.

Verbesina Verbesina and Zexmenia in Ecliptinae as it shares ment of these genera in subtribe Helianthinae as many features of Eclipta and Wedelia (Pandey and has been done by Stuessy (1 977). Encelia and Jh a unpublished). Lagascea ，however ，differs from Enceliopsis ，however ，deserve placement in a the the members of Ecliptinae in absence of thicken- separate group within Helianthinae. ings ings in seed coat cells but pericarp anatomical characters characters resemble to a great extent with those of Authors are greatful to Prof. K. S. Bilgrami ， the the other members of Ecliptinae (Pandey and Jha Head Department of Botany ，Bhagalpur Univer- unpublished). unpublished). We thus suggest the placement of sity ，Bhagalpur for providing facilities. Thanks are Lagascea in subtribe Ecliptinae together with also due to Prof. Tod F. Stuessy ，Department of Verbesina Verbesina and other members of this subtribe. Botany ，Ohio State University ，U.S.A. for pro- Encelia Encelia and Enceliopsis placed in subtribe viding mature achenes. Grant support (#38 (756)/ Helianthinae Helianthinae by Stuessy (1977) together with EMR 11 to AKP) from CSIR ，New Delhi is Helianthus ，Simsi 孔 Tithonia and Viguiera show thankfullyacknowledged. a similar basic pattem of seed coat and perica 中 References References differentiation. differentiation. These genera differ from other Hoffmann O. 1890. Tubuliflorae-Heliantheae and members of Helianthinae in characters like (i) Helenieae. In Die naturlichen Pflanzenfamilien (Engler and and Prantl ，eds.) 4: 21 0- 267. presence presence of continuous phytomelanin layer (ii) Robinson Robinson H. 1981. A revision of the tribal and subtribal presence presence of continuous fibre zone and (iii) presence limits of the Heliantheae (Asteraceae) Smithsonian Contr. Contr. Bo t. 51: 1-102. of of fibrous thickening in the seed coat cells. Mor- Stuessy Stuessy T. F. 1977. Heliantheae. Systematic review. In phological phological characters of Encelia and Enceliopsis Heywood V. H. ， Horborne J. B. and Turner B. L. resemble resemble to a great extent with other members of (eds.). The Biology and Chemistry of Compositae. London. London. subtribe subtribe Helianthinae ，therefore ，we support place-