TYPOLOGY OF FOLIAR SCLEREIDS IN VARIOUS TAXA OF BY T. ANANDA RAO (Botanical Survey of , 76, L.C. Road, Calcutta-14) AND O. P. BUUPAL (G. C. Bose Biological Research Unit. Bangabasi College, Calcutta-9) Received February 13, 1973 (Communicated by Prof. L. Narayana Rao, F.A.~.)

A~STRACT Sclereids of one type or the other in various combinations within the mesophyll of the several taxa of Hamamelidaceae are described in this paper. Furthermore the study suggests that the typology of sclereids in a few taxa segregated under taxonomic sub-division could be vtilised for evaluating the systematic value either for singling out a species or group of spocies within a and may also prove to be taxonomically significant in solving problems of synonymy.

INTRODUCTION HARMS (1930) has drawn attention to the fact that the taxonomic sub- divisions of the family exhibit corresponding anatomical differences. This applies particularly to the type of crystal in the mesophyll and to the distri- bution of sclerenchyma around the vascular bundles of the veins (Metcalfe and Chalk, 1950). Further, from the records available that 'sclerenchy- matous idioblasts ' of various types are reported in the mesophyll of Bucklan- dia (Exbucklandia), , Eustigma, Hamamelis, Dicoryphe, Distylium, Loropetalum and Sycopsis (Reinsch, 1890; Niedenzu, 1891; Solereder, 1908; Metcalfe and Chalk, 1950). Reinsch (1890, p. 360) was the first worker to report the intimate relationship between 'Spicular ceils' and the veinlets in the of Distylium and Loropetalum of this family. Foster (1947) has briefly mentioned the occurrence of terminal sclereids in Exbucklandia populnea (R. Br. ex Griflith) R. W. Brown, Eustigma oblongifolium Gard. and Champ. and Rhodoleia teysmenni Miq. Rao (1953, 1968) and Mody (1958) have confirmed the occurrence of terminal foliar sclereids in Exbuck- landia populnea (R. Br. ex Griffith)R. W. Brown, Bhupal and Kundu 127 128 T. ANANDA RAt) AND O. P. BIqHJPAL

(1969) and Rao (1973) have reported the intimate relationship of the sclereids and veinlets in the mesophyll of a few spzcies of Rhodoleia. In the present study the following herbarium specimens have been examined to find out the types of sclereids in various taxa of the family and their utility in taxo- nomic sub-divisions.

MATERIALS

Altingia excelsa Nor. Java, Kooders 232 (CAL); Yanan Expedition, Joneshee, Anderson, s.n. ; Burma, Kachin Hills, Pottinger, s.n. ; Java, Forbes 1201 (CAL) ; East Bengal, Griffith 3380 (CAL) ; Assam, Janakmukh, Burkill 37194 (CAL). Corylopsis himalayana Griff. India, Shillong, Carter 878 (CAL); Shillong, Clarke 44427 (CAL). C. manipurensie Harms (C. himalayana Griff. var. manipurensis) India, Manipur, Sirohifura N.E. range, Wall 6634 (CAL). Disanthus cercidifolium Maxim. Ex. Herb. bot. Metrpolitan, Maximowicz. Japonia, Prov. senanw Geg. Tichonasrci, Anon., (Ace. no. 1612533 CAL). Distylium indicum Benth. East Bengal, Griffith 3377 (CAL). Exbucklandiapopulnea (R. Br. ex Griflith) R. W. Brown [syn. Symingtonia populnea (R. Br. ex Gritiith Steen.)]; preserved specimen, T.A. Rao, Lloyd botanical garden, Darjeeling, India. Eustigmaoblongifolium Gard. et Champ. Kurz, Ford 1876 (CAL); , Dr. Aug. Henry's col- lection, Ford, Anon. (Ace. no. 1612335 CAL); Hongkong, Ry. gard. Kew, Ford. Anon. Forthergilla alnifolia L. f. Trianon, Anon. (Ace. No. 161128 CAL); Trianon Dollinger, Anon. (Ace. no. 161127 CAL). F. major (Sims) Loddiges, Trianon, N. C., Ex Biltmore 6565 (CAL) Hamamelis japonica Sieb. et Zuc. "Plantarum Asia Orientalis, Herb. S. jaeeave. Prov. Lwakl, Hayaikavas 67 (CAL); Ex. Herb. hort. bot. Metropolitan, Japonica Nippon, Tsehonosk, Anon. ~Ace. no. 161201 CAL); Communicated Ex herb. Metrpolitan, Lugdum, Anon. (Ace. no. 161203 CAL). H. japonica Sieb. et Zuce. f: Yoshidai Hiyama Tokyo, O]zumi, Nerima-ku, Tomitaro Makino 40361 (CAL). H. japonica Sieb et Zuce. var. bitchuensis (Makino) Chwi Japan, Hyogo, T. Makino 40191 (CAL). H. japonica Sieb. et Zuce. var. discolor Hiyama f: incarnate Ohwi, Tokyo, Oisumi, Nerima-ku, T. Makino 40216 (CA/.,). H. japonica Sieb et Zuce. var. discolor Hiyama f: obtusaat I-Iiyama Japan, Hyogo, Aoba, T. Makino 40233 (CAL.) H. japonica Sieb et Zuce. var. flavo-purpurascens Rheder Tokyo, Oizumi, Harima-ku. T. Makino 40285 (CAL). H. mollis Oliv. Central China, Henry 3791 and 4612 (CAL). H. vitginiana L., U.S.A., New York; Tompkins country Mac. Daniels 4266 (CAL); Stoneham, Mass, Anon. (Ace. no. 1611207 CAL); Florida, Oadsden country, Geo. V. Nash 2385 (CAL, ; U.S.A. Chicago, H. I-L Typology of Foliar Selereids in Various Taxa ,f Hamamelidaceae 129

Babcock, s.n. (Ace. no. 161209 CAL). Liquidamber chinensis Champ. Hongkong, Ford s.n. (Ace. No. 161327 CAL). L. formosapa Hance China, , Fung. H. 20245 (CAL); China, Kweichow province, Albert. Stre- ward, C. Y. Chen. 7630 (CAL)and 5218 (CAL); Japan, Taiwan, T. Taneka and Y. Swmada 13490 (CAL). L. styraciflua L. Central Peninsular Florida, Lake country, Geo V. Nash s.n. (Ace. no 161337 and 161338 CAL)t~ L. tricuspis Miq. Sumatra, O. Beecari 399 (CA[,). Loropetalum chinches Oliv. (Hamamelis chinensis R. Br.) Assam, Prain 96 (CAL); Assam, K. and J. hills, U. Kanjilal 353 (CAL) (P). Maingaya malayana Oliv. Malaya, Herb. of Maingaya 1523 (CAL) (Distributed by Kew); Malaya, Kunstler 7330 (CAL) Sycopsis griffithiana Oliv. Griffith 3375 (CAL); Assam, Khasi hills, Kanjilal 7330 (CAL); Malaya, Penang, Cameroris high lands, Hinder- son 23567 (CAL). Trichocladus crinatus Pers. Africa, Zululand, Wylie and Wood 10318 (CAL); Locality not known, A. C. Meaneder 1847 (CAL). T. ellipticus E. et K. Natal, Schlechter 6115 (CAL). Following the synoptic classificatory system of Hamamelidaceae by Harms (LEO, a brief account on the position and combination of foliar sele- reids in the lamina of varied taxa is given below.

Sub-family: DISANTHOI DEAE Genus : Disanthus In the leaf clearings of Disanthus cercidifolium Maxim. terminal or sub-terminal selereids have been observed (Fig. 4). In transections they are oriented in the mid-mesophyll region with their arrested branches protrud- ing among palisade and spongy cells (Fig. 3.) The selereids type usually conform to fusiform type. From such a simple type, a gradual series can be built to 'Y' or 'T '-shaped forms. Polymorphic selereids conform to symmetrical astrosclereids or asymmetrical polyramous type sensu Rao and" Bhupal (1973). Structurally, both the forms of selereids have a smooth outline except for the presence of a few spicules.

Sub-family: HAMAMELIDOIDEAE Tribe: HAMAMELIDEAB Genus: ttamamelis Cleared of H. molli~ Oliv., hr. virginiana L. and H. japonica Siob et Zuc~ ,Mth its varieties and forms: H. japonica f: Yo~htden 130 T. ANANOA RAO AND O. P. BItUPAL

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Fins. 1-4. Figs. 1 and 2. S¢lot'eidl of llamameli.t mo//~. Fii~. 3 and 4. SeJemide of Disanthus cercldifollum. Typology of Foliar Sclereids in Various Taxa of Hamarnelidaceae 131

Hiyama, H. japonica var. bitchnensia (Makino) Ohwi, H. japonica var. discolor Hiyama f. lncarnata Ohwi, H. japonica var. discolor Hiyama f: obtusata Hiyama and H. japonica var. flavopurpurescens Rheder have been investigated. No sclereids have been observed in any of them except H. mollis. The absence of sclereids in H. virginiana is puzzling because polymorphic terminal sclereids of varied size and form have been reported in the same species by many authors.

Sclereids of H. mollis conform to three main base forms : osteosclereids, fusiform sclereids sensu Rao (1953) and rhizosclereids sensu Richter (1920) with many intermediary stages (Fig. 1). In the leaf clearing they are sparingly distributed and in transections the form conspicuous idioblasts in the mesc- phyll (Fig. 2). Some of them are ' Y' or ' T '-shaped with striated cell wall, rarely spiculated and possess lumina of irregular width.

Genus : Loropetalum

The cleared leaf preparations as well as transections the leaves in L. chinense revealed the presence of sclereids of a peculiar kind. They resemble vascular fibres and are disposed close to the minor veins and veinlets. They constitute extraxylary idiofibrosclereids (Rao and Bhupal, 1971). In leaf clearings, they appear as fibres leaving their main path and traversing into adjacent tissues of the leaf expanse. In transections, they are obliquely oriented and sometimes branches run parallel to epidermal layers. Morpho- logically, they resemble vascular fibres but could be easily distinguished from them by their bizarre ends, bigger transectional area, uneven wall thickening and lumen of irregular width.

Genus: Trichocladus In the two species examined, viz., T. ellipticus E. et K. and T. crinatu~ Pres. foliar sclereids were absent in T. ellipticus but extraxylary idiofibro- sclereids were present in T. crinatus which in general appearance show the same features as described in Loropetalum chinense.

Genus : Maingaya One species of this genus M. malayana Oliv. was examined. The cleared leaf preparations as well as transections revealed that no sclereids were present in any part of the leaf expanse. 132 T. ANANDA RAO AND O. P. BHUPAL

Tribe : EUSTIGMATEAE Genus : Eustigma Cleared lamina of this monotypic genera E. ob/ongifoliurn Garden et Champ. shows the presence of terminal or sub-terminal sclereids (Fig. 7). In transections they are more or less vertically oriented and occasionall2¢ touch the epidermal layers (Fig. 8). Foliar sclereids conform to osteoscle- reid type. From this base form it is not uncommon to find rhizosclereids (Figs. 7 and 8) showing crookedly branching ends facing the spongy area

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FIGS. 5 and t,. Sclereids of Liq,'ddamber tricu~pi.~. Typology of Foliar Sclereids in Various Taxa of ttamameltdaceae 133

Structurally, selereids have thick striated cell wall and possess lumhaa of irregular width.

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Fras. "/ and 8. Sclereids of Eustigma oblongtfollum.

Tribe : CORYLOPSIDEAE Genus : Corylopsis In cleared laminae of the two species examined, viz., 6"). himalayana Griff. and C. manipurensis Harms sclereids were not noticed in the mesophyll tissue. Tribe: FORTHERGILLEA)~ Genus : Forthergilla In cleared laminae of both the species, viz., F. a,'n:,folia L. f. and L. mcdor (Sims.) Loddiges, sclereids were not observed in the mesophyll tissue. 134 T. ANANDA RAO AND O. P. BHUPAL

Tribe : DISTYLIEAE Genus : Distylium

Distylium indicum Benth. was examined for the presence of foliar scle- reids in the mesophyll tissue. The cleared leaf preparations revealed the presence of extraxylary idiofibrosclereids along the main secondary veins. They often exhibit criss-cross pattern and in transections they appear as idioblastic sclereids. Structurally, they conform to the descriptions already described.

Genus : Sycopsis The leaf clearings of Sycopsis griffithiana Oliv. was examined. The presence of extra xylaryidiofibrosclereids in abundance along the major and minor veins as well as at the terminus of veinlets were found through- out the leaf expanse.

Sub-family: RHODOLEIODEAE Genus : RhodoMa Recently the genus has been examined by Bhupal and Kundu (1969). The leaf clearings as well as transections of the leaves of four species exa- mined, namely, R. ehampioni Hook. f., R. ovalifolia'., Ridl., R. subcordata, Exell and R. teysmanni Miq., terminal or subterminal sclereids were present in the mesophyll tissue. The simple type chiefly conforms to Osteosclereids, rhizosclereids, 'I '-shaped sclereids and its modifications. The polymor- phic type is represented mainly by polyramous sclereids (Rao and Bhupal, 1973). All types of sclereids have been seen in one and the same leaf.

Sub-family: BUCKLANDIODEAE Genus : Bucklandia The leaf clearings as well as transections of the leaves of Exbucklandia populnea (R. Br. ex Grittith) R. W. Brown show terminal polymorphic sclereids belonging to the categories of astrosclereids and polyramous scle- reids (Fig. 9). Richter (1920), Foster (1947), Rao (1955, 1968) and Mody (1958) have reported the occurrence of terminal sclereids in the mesophyll of this species. Typolegy of Foliar Sclereids in Various Taxa of Hamamelidaceae 135 The present work supports the detailed observations of Rao (1968). Struc- turally the sclereids have smooth outline, striated secondary wall and luminae of irregular width. They often exhibit branching leading to symmetrical astrosclereids or asymmetrical polyramous sclereids (Figs. 9 and 10).

1T ! [~1] I • In I |'1 I-1 l" " [- • - i ,, ";.; ':':~'.~',o..;;'.,'.- ~.., ~,~< .~ '" ":~ i: .,'.' *'....o :,,) ~ ~.i "-., .'.

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FIGS. 9 and 10. Sclercids of Exbucklandia popul~6a.

Acad.--B 3 136 T. ANANDA RAO AND O. P. BHUPAL

Sub-family: LIQUIDAMBAROIDEAE Genus : Liquidamber In the four species, namely, L. chinensis Champ., L.formosana Hance, L. styrac~fluca L. and L. tricuspis Miq. examined, terminal polymorphic sclereids of the category of polyramous sclereids are encountered only in the mesophyll tissue of L. tricuspis Miq. (Fig. 6). In the other species, no sclereids were observed.

The sclereids of L. tricuspis are peculiar cell forms. Mostly they are asymmetrical forms due to repeated irregular short branches (Fig. 5). The sclereids have thick, striated cell wall, short arrested branches and lumina of irregular width.

Genus : Altingia In the species examined, viz., A. excelsa Nor. no sclereids were found to be present.

CONCLUSION The present study suggests that the typology of sclereids in a few taxa segregated under taxonomic sub-division could be utilised as a promising source of systematically valuable criteria. Of the several taxa re-examined sclereids of one type or the other in various combinations within the meso- phyll are recorded in the following taxa: fusiform to polyramous sclereids in Disanthus of Disanthoideae, fusiform, osteo and rhizosclereids in Hama- melis, osteo and rhizosclereids in Eustigma, idiofibrosclereids in Loro. petalum, Trichocladus, Distylium and Sycopsis of Hamamelidoideae, osteo and polyramous sclereids in Rhodoleria of Rhodoleiodeae and astro and poly- famous sclereids in Exbucklandia of Bucklandiodeae. The detailed study has shown that the typology of sclereids are useful in singling out a species or group of species with a genus. However their absence in Maingaya, Corylopsis, Forthergilla of Hamamelidoideae andin all the species of Liquidam- beroideae leads to the conclusion that there may be some justification for the removal of Liquidamber and Altingia from Hamamelidacoae to an inde- pendent family Altingaceae. Similar reasoning may be thought of for removing Maingaya, Corylopsis and Fothergilla from the subfamily Hama- melidoideae if adequate other characters are elucidated in the future studies in the systematics of this sub-family. Typology of l~bliar Selereids in Various Taxa of Hamamelidaceae 137

Clarke (1858) and Vink (1957)have considered Liquidamber tricuspis Miq. as synonymous with Exbucklandia populnea (R. Br. ex Griff.) R. W. Brown. Further, ;Clarke is of the opinion that Malayan Liquidamber tri- cuspis does not differ in the smallest point from Himalayan specimens of Exbucklandia populnea some of which have tricuspidate leaves and seri- ceous petioles. The sclereid morphology clearly indicates that in Exbuck- landia populnea sdereids are asterosclereids and polyramous sclereids with terminal or sub-terminal disposition with reference to their veinlet endings. Often they are found clustering round the minor and major veins forming more or less a loose protective covering. As a contrast to this orientation, the cleared laminae and transections of Liquidamber tricuspis show poly- famous sclereids, relatively bigger than that of Exbucklandia populnea and form distinct idioblasts inside the mid-mesophyll region. At no stage they have close juxtaposition with the main veins and veinlets, but appear in twos or threes at the veinlet endings. In view of the characteristic sclereid orien- tation in the leaf of Liquidamber tricuspis, Clarke's attempt to consider this species as synonym of Exbueklandia populnea needs critical study. The sclereid pattern supplemented by the histology of leaf and stem may be useful in re-examining the real status of these taxa. It is of interest to remember that no sclereids have been reported in the genus Liquidamber. Of the two species of Altingia only A. excelsa Nor. was examined. It was found that the leaf expanse in this species was com- pletely devoid of sclereids. The absence of foliar sclereids are very charac- teristic of the genus Liquidamber and Clarke's treatment of Liquidamber altingia BI. as synonymous with Altingia excelsa Nor. in all probability seems to be correct.

ACKNOWLEDGEMENT We wish to thank Dr. K. Subramanyam for kind encouragement.

REFERENCES

Bhupal, O. P. and Kundu, "Systematics of Rhodoleia with reference to sclereid morpho- B.C. logy," Trans. Bose Res. btst., 1969, 32. Clarke, C. B. Flora of British India., 1882, 3, 611. Foster, A. S. "Structure and ontogeny of the terminal sclereids in the leaf of Mouriria huberi Aubl.," J. drnoM Arbo., 1947, 27, 253-71.

Harms, H. E. N.K. .. "Hamamelidaceae," Die naturl. Pflanzenfam., 1930, 2, 18A. 138 T. ANANDA RAO AND O. P. BHUPAL

Metcalfe, C. R. and Chalk, L... Anatomy of Dicotyledons, Vols. I and II, Clarendon Press, Oxford, 1950. Mody, K. .. "Comparative morphology of foliar sclereids in Angiosperms," M.Sc. Thesis, Gujarat University, 1958. Niedenzu, P. de .. "Hamamelidaceae," Die Naturl. Pflanzanfam, 1891, 3, 116-17, Reinsch, A. .. "Uber die anatomischen verhaltiniase der Hamamelidaccao mit systematische Gruppierung," Bet. JaMb., 1890, 2, 347-95. Rao, T. A. .. "Studies on foliar sclereids in seed ," Ph.D. Thesis, Mysore University, 1953...... and Bhupal, O. P. .. "Idiofibrosclereids, a new descriptive term for wandering mesophyll fibers," Curt. Sci., 1971, 40, 551. .. "Typology of sclereids," Prec. Indian Acad. Sci., 1973, 77 B, 41-55.

Rao, T. A. .. "Distributional pattern of sclereids in the leaf and stipules of Symingtonia populnea," [Curr. Sci., 1968, 37, 352-54. .. "Foliar sclereids in Rhodoleia teysmanni," Ibid., 1973, 42, 245-47. Richter, A. .. Math. Naturw. Berichte Ungarn, 1972, 31, 65-146.

Solereder, H. .. Systematic Anatomy of the Dicotyledons, Vols. I and II, Clarendon Press, 1908. Vink, W. .. "Hamamelidaceae," Flora Malesiana, 1957, 5, 371-79.