Pino. Indian Acad. Sal. ( Sal.), Vol. 91, Number 6, Decvmbet 1982, pp. 509-~17. ~~) Printcd in India.

Taxonomic importante of epidermai characters in the Indian Con'. 0VIalvar

S RAJA SHANMUKHA RAO and N RAMAYYA* Dopartmont of Botany, Saldar Patel Collego, Secunderabad 500025, India * Dcpartment of Botany, Osmania University, Hyder91 500 007, India

MS received 4 Det;ember 1981 ; revised 21 October 1982

Abstract. In Thespesia lampas and. T. populnea, the foliar stomata aro aniso91 anomocytic anct tetracytic, the first type being dominant. Further in Thaspesia lampas and. T. populnea altogether eight triehome types are reeognisable mostly on the basis of structure. The two speoies can be d.istinguished from each other by the presence of multiseriate aseptato stellate hair in the former and that of multiseriato aseptate peltate haL in the latter. T. populnea is also distinet from that of T. /ampas due to curved, to wavy epir waUs, striated, surface, absence of mueilaginous cells on the leaf abaxial. The present evid.ence also supports treat mcnt of I". lampas un(ter Thespesia rather than in .

Keywords. Epidermal characters ; ; Thespesia ; Malvaeeae.

1. Introduction

Taxonomic importanee of epidermal oharaotors in general and those of trichomes in particular in angiospermous is now widely reoognisod (Pmt 1932; Tomlinson 1961 ; Stace 1965 ; Ghose and Davis 1973 ; Verhoevon and Schijff 1973). Howev~, previous studi~s on the epid~mis ate limited to few taxa and only to certain aspeets in tha (Soleroder 1908; Metcalfe and Chalk 1950 ; Iaaamdar and Ckohan 1969; Ramayya and Shanmukha Rao 1976; Shan- muktm Rao and Ramayya 1977a, b). Henee, the present investigation w'91under- tak•n whioh de,als with foliar opidermal charaoters along with struoturo and organographio distribution of t¡ in whole plant and their taxonomic importaneo in the two Indian Thespesia.

2. Material and methods

The material of Thespesia lampas Dalz. & Gibs. was eolleeted from Car.amjol, Goa, wheteas T. populnea (L.) Sol. ex Corr. from plants growing at Sardar Patel

509 510 S Raja Shanmukha Rao and N Ramayya Colicge campus, Socunderabad. Maturo triohomos worc studied eithcr from epidormal pedings of those isolated by s~aping the plant parte. Thcse micro- prepamtions wcre stained cither with anilin bluo in laotophcnol oF safranin, hematoxylin and then mountod in 7070 glyoe¡ Boiling the material with 5-1070 glacial aoetio acid was useful in obtainiug the pecls. Miorotome scctions of shoot apiccs were cut at 10-14t~m thiokncss and stainod with hematoxylin and basio fuchsin. The foot of the different ~iohomcs was det~minod in free- hand and rniorotome seotions of various parts of the species investigat•d. The walls of the digerent t¡ wcrc tested with phloroglucin and 270 HCI for li~in (Johansen 1940). The torras desofibing stomatal types ate aftor Metoalfe and Chalk (1950) and as rodo¡ by Shanmukha Rs and Ramayya (1977a) and for trichome types, aftor Ramayya (1972) and Shanmukha Rao and Ramayya (1977b).

3. Olmervations

3.1. Structure and distribution of epidermal and stomatal complexes on the leaf 3. la. Epidermal cell complex : Epidormal coUs : 4-6-si• anisodiamet¡ ; eontents dense, brownish in T. populnea; sides thin, s~aight (leaf abaxial and adaxial of T. lampas and leal adaxial of T. populnea) of curved to wavy (leafabaxial of T. populnea) ; surfaoe smooth (T. lampas) of striatod (T. populnea), st¡ wavy, prominent and continuous. Distribut[on: Confined to the interstices, vafiously oriented (figures 1-4). Costal cells : 4-sided, linear; contents soanty of mostly brownish (T. populnea); sides modemtely thiek, straight of eurved (leaŸ abaxial of T. populnea) ; surfaoe smooth (T. lampas) oF st¡ (T. populnea). Disttibution : O¡ par.alld to the veins, diffuse. Mueilaginous c~lls : Similar to the epid~mal colls but enlarged below with opaque contente ; sides thin, stmight of eurved ; suffaeo smooth. Distr/bution: Oeeas,.'onal eith6w in lr abaxial (7'. lampas) of adaxial (T. lampas and T. populnea) (figures 4 and 10), 3.1b. Stomatal complex: Stomata mostly anisoeytie, oooasionally anomocytie of tetmcytie. Suhsidiaries 3 oF 4, monocyelic unequal, similar to the epidermal oolls oxeept that euticular stfiations are absent over stomata. Distribution: Amphistomatie but adaxially stomata confined to margins of the midrib (figures 1-6). Data on the epidermal and stomataI complexes are given in table 1. In both the species, single guard c~lls as stomatal abnormality ate ocoasionalIy observ6xl in the leal abaxial wherea~ they aro totalIy absent in the adaxial (figure 7). 3.2. Structure and distribution of trichome complex on vegetative and floral parte Eight triehome types could be re~ognis~xt in the two speoies, viz., O) unicellular conical hiax, (ii) uniseriato filiform clavate hair, (iii) uniseriate ¡ pyriform hair, (ir) multise~iate aseptate peltate hair, (v) multiseriatr ascptate stollate hair, (vi) multiseriate aseptato 4-arm~ stellate hair, (vii) multiseriate aseptate 3-armed ste,llatr hair and (viii) bisr asoptato V-shaped hair. The details of the struc- tufo of the triohomo types aro as follows : Taxonomic importance of epidermal characters in Thespesia 511

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Figures 1-U. Epidermis of Thespesia. T. populnea : 1 and 2. SurIh.eo views of lr abaxial and. adaxial respectively (r stiiations not drawn). 7. Surface view of stomatal abnormality wittt single guard. ,cll from leafabaxial. 10. Mucflaginous coll from leal abaxial epidermis in "r.s. 11. Oblipu• seotion showing sunken uniseriatc filiform elavate hair from T.S. leaf (foot ccll not visible). 7". lampas : 3 anct 4. Surfaee views of leaf abaxiial and adaxial respeetively. 5. Semi- d.iagrammaticrepresentation ofstomatal distribution eonfined to margins of midxib from leal adaxial. 6. Suffaee view of anomoeytie stoma from leal adaxial. 8. Unisr filifoirm clavate hair ti-oro T.s. l~dicel. 9. Sido view of emergenr from pedicel. (me = maeilaginOuS cr

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Figures 12-28. Epidermis of Thespesia. 7". populnea: 12. Multiseriate aseptate pr hair from leaf abaxial. 13-15. Intcrmediates between multiseriate aseptatc p9 hair and. mtdtiseriate aseptate stellate hair frcm petal abaxial. 16. Multi- s9 ascptato stellate hair from peral abaxial. 17. Isolated. unicellular conical hair from sepal ad.axial. 27. Uniseriate filiform pyriform hair of nor from sr adaxial. T. lampas: 18. Unicellular conical hair from scpal adaxial. 19, 2Q. Biseriato V-shaped. aseptato hair from sepal adaxial and petal abaxial rr 21, 22. Multiseriate asoptato 3-armed stellato hair from petal abaxial. 23. Surface view of uniscriate ¡ clavate hair from pedJcel. 24, 25. h,[ultiscriate aseptato stellato hair from leaf abaxial and pedicel respeetively. 291Mulª aseptato 4-armed stellate hair from ovary. 28. Uniseriato filiform pyriform hair of nectary from sr adaxial. 514 S Raja Shanmukha Rao and N Ramayya

3.2a. Unicellular conical hair: Foot consisting of the basa! end of the body cell, indistinct from the body, embedded in the epidermis ; neighbouring eeUs of foot annular and striated; contents abscnt; waU thick. Body representing extension of the foot, conical, apically pointed ; contents absent ; waU thiek and nonligni¡ ; surfaee smooth (figures 17 and 18).

3.2b. Uniseriate filiform clavate hair: Foot 1-celled, square to linear of trape- zoidal, embedded of p~ojected above the epidermis; contents absent, waU thin. Stalk 1-celled, rectangular to linear ; contents seanty ; waU thin ; surface smooth. Head clarete, 2-6-tiered, eaek tier 2-6-oelled ; eeUs square to linear; contents dense; waUs tlª surface smooth (figures 8, 11 and 23).

3.2c. Uniseriate filiform pyriform hair: Foot 1-celled, linear, embedded or projected above the epidermis; contents absent; waU thin. Stalk 1-celled, rectangular to linea~ ; contents scanty ; waU thin ; surface smooth. Head pyri- form, multiseriate, 4-10-tiered, each tier 2-6-ceUed, generally terminated by a pair of rounded eeUs ; ceUs rectangular to linear ; contents dense ; walls thin ; surfac~ smooth (figures 27, 28).

3.2d. Multiseriate aseptate peltate hair : Foot narrow, consisting of the juxta- posed basal ends of the 20-35-body ceUs, embedded in the epidermis, polygonal in outline in peels mounted upside down, occasionaUy subtended by ah emergente ; contents absent ; walls thin, nonl2gnified. Body peltate, nearly circular of uneven, serrate of erenulate at margin, 20-35-armed, representing continuation of tho foot ; arms broadened near the centre of the body but tape¡ towards distal end, paraUel to the epidermis ; eontents brown ; walls thin, nonlig-nified ; surface smooth (figure 12).

3.2e. Multiseriate aseptate stellate hair: Foot es in the above. Body stellate, 5--40-armed, representing confinuation of the foot; amas tapering towards the distal end, unequal in length, generalIy paraUel to the epidermis, some obliquely raised above ; contents absent ; waUs thin to mod~atety thick, nonª ; surfaco smooth (figures 9, 16, 24 and 25). Multiseriate aseptate 4-armed stellate hair, muItiseriate aseptate 3-armed steUate hair and biseriate aseptate V-shaped hair types ate similar to the multi- seriate aseptate stet[ate hair described above except for the difference in number of arms of the body as indicated by the names of triettome types (figures 19-22 and 26). The details of distribution of the various triehome types ate given in table 2.

4. Discussion

Inamdar and Chohan (1969) record~ anisocytic and anomocytic stomata in Thespesia populnea, which is presenfly confirmed. Further, tetracytic stomata (es defined by Shanmukha Rao and Ramayya 1977a) have also been presently not in the leaves of the two species of Thespesia studied. Among the thtee stom:ttal types, the anisocytir is dominant (table 1). Taxonomic importance of epidermal charactem in Thespesia 515

Table 2. Organographie distribution of triehome types in the Indian ThespeJia.

Plant part Thespesia lampas Thespesiapopulnaa

Leaf abaxial B, E B, D Leal adaxial B, E B, D Leaf margin A, E B, D Pctiole B, E B, D Stipulr abaxial B, E B, D Stipule adaxial B, E B, D Stipule mŸ B, E D Stem B, E B, D Peduncle B. E B. D Bracteole abaxial B, E B, D Bracteole adaxial B B, D Brac:eole margin B, E D Scpal abaxiel .-. B, D Scpal adaxial A, C, H A, C Sepal margin A A Petal abaxial A, E-H B, E-H Petal adaxial ...... Petal margin A, E-H A Staminal tube ...... Style ...... Ovary A, E-H D

A, Uni~llular e~a~cal h:dr ; B, Unis~riate filifcrm clavate hair ; C, Unisr filiform pyriform hair ; D, Multisr aseptate pr hair ; E, Multiseriate aseptate stellate haix ; F, Multiseriatc ascptate 4-armed. stellate hair ; G, Multiseriate eseptate 3-0rmed stellate hair ; H, Biseriate asel,tate V-shaped hair.

According to Youngman and Pande (1929) the foltowing trichome typ~ oocur in Thespesia : (i) single unbranch~xi hairs, (ii) steUate hairs, (iii) peltato se,ales and 0v) club shaped bodŸ The first and third tr.iohomo types quoted above ate the same as the uniceUular conioal and multise~iate aseptate peltate hair types respecfively, desoribed by us. On the other hand, we oonsider the "stellate hair" type quoted above, to be a triohome complex r.atheg than representing a speoific trichome type. On oomparison with the trichome types delimitexi in the present investigation, the stellatc hair is lesolvable into the following four tyl~s : (i) multi- sr aseptate stellate hair, (ª aseptate 4-armed stdlate hair, (¡ multiseriate aseptate 3-mmed stellate ha.ir and (ir) biseriate aseptate V-shaped hair. Similarly the olub shaped body is distinguishable into two of the prcsently desoribed trichomo types : (i)unis~iate filiform clavate hair ami (ª filJform pyriform hair. In the two speoies of Thespesia invr thus in al] eight trichome types aro presently reoognisable as desorŸ in the text. 516 S Raja Shanmukha Rao and N Ramayya

Though, in T. lampas, the multiseriate aseptate stellate hair on pedicel and sepal abaxial ate 5 to many armed (figure 25), those on the leal lamina, petiole and stem are 20-40-armed with thin waUs (figure 24). Likewiso in T. populnea the arms of the multiseriate aseptate peltate hair are 20-35 with thin walls on all the parts of its oceurrenee (figure 12). Many intermediate forms oonneeting the peltate and steUate types also occur on petals (figures 12-16). The ehameters whioh distinguish the multiseriate aseptate stellate hair of T. lampas and the multiseriate aseptate peltate hair of T. populnea from each other inelude the separate and tapering rtature of the arras in the forme~ and the conp_ate condition and rounded ends of the arms in the latterr (figures 12 and 24). As shown by Ramayya ana Shanmukha Rao (1976) the above differenees in the two triehome types are due to early onset of apical intrusive growth instead of symplastic growth in the development of arras in the multiseriate aseptate steUate hair. Thus the differences desoribed ate deep in origin and henee ate signi¡ in justifying the separation of the two trichome types. In the two speeies of Thespesia, aU the vegr parts are trŸ whereas in the floral parts, the surfaee of the peral adaxial, staminal tube and stylo aro non-triehJferous (table 2). Further, in eaeh of the speoies, aU the tdchiferous parts show at least two trichome types (viz., multiseriate aseptate peltate hair and uniseriate filiform clavate hair, in T. populnea and multiseriate aseptate stellate hair and uniseriate ¡ clavate hair in T. lampas) except the abaxial surfaee of the petal and the ovary whioh possess several triehome types eaoh (table 2). Out of the eight trichome types now deseribed, aH of them oocur in T. populnea whereas in T. lampas there ate seven types, the multisoriate aseptate peltate hair being absent (table 2). Thus the two species ate distinguished from eaeh other due to the presenee of the multiseriate aseptate peltate hair in the former and that of the multise¡ aseptate stellate hair in the latter. Further, the leaves of T. populnea ate distinot from those of T. lampas by eurved epidormal eells with st¡ and absenoe of mueilaginous cells on the abaxial surfaees (table 1). In the systematio aocounts, Thespesia lampas (Masters 1874 ; Borssum 1966 ; Rakshit and Kundu 1970 ; Saldanha and Nioolson 1976) is oonsidered oonspecifie with Hibiscus lampas (Sehumann 1890; Hoehr.eutiner 1900; Gamble 1957) and lampas (Babu 1977). The tribe (ineludes Thespesia) dŸ from (ineludes Hibiscus) by the gossypol glands and conduplioate embryos (Fryxell 1968). The presence of gossypol glands on different parts of Thespesia lampas, T. populnea and other two species (Standford and Viehoever 1918; Lukefahr and FryxeU 1967) supports the separation of Thespesia from Hibiscus. Further, Thespesia lampas star.ds out distinct in other Malvaceae (with thick-walled non-lignified stellate hair) by the multiseriate aseptate thin-walled stellate hair, thus providing further evidente to treat Thespesia larnpas distinet from Hibiscus lampas.

Acknowledgement

Orto of the authors (SRR) is thankful to the Prinoipal, Sardar Patel CoUoge, Seounderabad, for providing faoilities. Taxonomic importance of epidermal characters Ÿ ThespesŸ 517

Referenr

Babu C R 1977 Herbaceous flora of Dehradun (New Delhi : csm) 84 Borssum Waalkes J Van 1966 Malesian Malvar revised ; Blumea 14 1-251 Fryxell P A 1968 A redefinition of the tribe Gossypieae ; Bot. Gaz. 129 296-308 GambIe T S 1957 Flora of the Presidency of Madras (Reprinte4 ed.) (Caleutta : nsl) Vol. 1 p. 72 Ghose M an4 Davis T A 1973 Stora~ta and trichomes in leaves of young an4 adult palms ; Phytomorphology 23 216-229 Hochreutiner B P G 1900 Kcvision du genera Hibiscus ; Amt. Cons. Jard. Bot. Geneve 4 23-91 Inamdar J A and Chohan A J 1969 Epi4ermal stmcture and stomatal development in some Malvaceae and Bombacaceae ; Ann. Bot. 33 865-878 Johansen D A 1940 Plm, t raicrotechnique (New York : N[eGraw-I-Iil[ Book Co., Isla.) 194 Lukefahr /vi J and Fryxell P A 1967 Cant•nt of gossypol in plants belonging to genera lela- ted to cotton ; Ecm~. Bot. 21 128-131 Mar M T 1874 Malvacr191 in The flora of British India (ed) J D Hooker (London : Reeve and Co.) Vol. 1 184 Metcalfe C ti. and Chalk L 1950 Anatomy of the dicotyledons (Oxford : Claren4on Press) Vols. 1 and2 Ptat H 1932 L" Epi4erme des Graminees ; Annales des Scier.ces Naturelles Botanique et Biologie Vegetate Series 10 165-258 Rakshit S C and. Ktmdu B C 1970 Rr of the Indian species of Hibiscus ; BulL Bot. Survo India 12 151-175 Ramayya N 1972 Classification and. phylogeny of the trichomes of angiosperms in Research zrenda in plant anatomy K A Chowdlxury Commemoration Volume (eds) A K NI Ghouse ah4 lV[ Ytmus (Now Delhi : Tata-M.eGraw-Hill) 91-102 Rama}ya N ami Shanmuktm Rao S K 1976 lVs phylesis and biology of the peltat~ sea.lo stellate ah4 tufted hair in some Malvaceae ; J. Indian Bot. Soc. 55 75-79 Saldanha C J and Nicolson D H 1976 Flora of Hassan District Karnataka In4ia (Ncw Del• ; Amaxind. Publishing Company) Vol. 1, ppd 15-'-i-'6. Sehtunann K M 1890 Malvaceae In Die na:urlichen pflanzenfamilien (eds) H G A Engler and K A E Pra~tl 3 Shanmukha Rao S R and Ramayya N 1977a Stomatogenesis in the genus Hibiscus L (Malvaceae) ; Bot. J. L/nn. Soc. 74 47-56 Shanmukha Rao S R and Rama}ya N 1977b Structure distribution and taxonomic importancr of trichomes in the Indian species of Malvastrum : Phytomorphology 27 40-44 Soleredor H 1908 •ystematic anatorny of the dicotyledons (Oxfor6 : Claren4on Press) Vols. 1 and 2 Stace C A 1965 The .~ignificance of the leal epidermis in the taxonomy of the Combretaceae I. A general review of tribal, generic and specific characters ; Bot. J. Linn. Soc. 59 229-252 Stsnford E E and Viehocver A 1918 Chemistry and histology of the glands of the cotton ylant with notes on the oc,currence of similar gl in related plants ; J. Agric. Res. 13 419-435 Tomª P B 1961 Anatomy of the monoeotyledons. II. Palmae (Oxford : Clarendon Press) pp. 30-31 Verhoeven R L and Schijff H P V D 1973 A key to the South Afxican Combretaceae based on anatomical characteristics of leaf ; Phytomorphology 23 65-74 Youngnmn W and Pande S S 1929 The epidermal outgrowths of the genera Thespesia and Gossy. p¨ ; Ann. Bot. 43 711-740