Typology of Sclereids 45

TYPOLOGY OF SCLEREiD, c

BY T. ANANDA RAO (Botanical Survey of India, Calcutta-14) AND O. P. BHUPAL [G. C. Bose Biological Research Unit (Bangabasi College) Calcutta-9]

Rec.civod January 1, 1972 (Communicated by Prof. L. Narayana Rao, F.A.S¢.)

ABSTRACT

A resume on the morphological types of sclereids has been given under various typological heads with example drawn from the published literature to enhance their utility as distinct types in detailed description of sclereids. Depending on the constancy of the body shape the sclereids are classified into two main subdivisions : Monomorphic and Polymorphic. With some reservation, within the scope of the two subdivisions many types are recognised. It is emphasised that each type is a descriptive unit reeognised for purpose of cogency in understanding.

INTRODUCTION

IN recent years the information on the main morphological types of sclereids and their variability has reached a stage of considerable interest in respect of other discipfines of Botany. The pioneer researcher in this field was Tschirch (1889) who for the first time recognised four main categories of sclerdds : brachysclereids, macrosclereids, osteosclcreids, astrosclereids. Subsequent workers have ufilised the above categories while describing sclereids found in their studies (Solereder, 1908). "In recent years a few workers have established the existence of different types of sclercids in several species of the same genus or several genera of a family by utilising a qualifying description to such forms which differ from the main categories recognised by Tschirch (1889).

Foster (1946), who rekindled interest on sclereid morphology taking the precaution of citing the voucher specimens has distinguished four types 41 Acid.-- B 1 42 T. ANANDA RAO AND O. P. BHUPAL of sclercidsin the genus Mouriria: parenchymatous cell form with or without radiating branches, ramified sclercids of stellate and fusiform branched or unbranched types and filiformor thread-likesclercids with or without forking. Following on the same lines Rao (1957 a) has recorded filiform branched or unbranched sclereids and polymorphic sclereids including spheroidal, fusiform and columnar sclereids with their modifications and stellate sclereids in 95 species of the genus Memecylon. Richter (1920) has rccogniscd in the family Marcgraviaceae a few categories of sclereids: ophiurosclercids, librosclereids, astrosclereids, palosclcrcids, rhizosclereids and idiosclereids. Working on the same family De Roon (1967) has adopted eight main categories of sclereids five of which already recognised by Richter (1920) and three of Tschirch (1889); brachysclereid, astrosclereid and oestosclereid. Singh (1967) has categorised four types of sclercids in 15 species of the genus Fagraea; aster, columnar, T-shaped and dcndroid forms. Rao described vesiculose sclereids in Scherebera swieteniodes Roxb. (1949, 1950 b), Leucospermum conocarpum R. Br. and Loranthus sp. Further, he recognised filiform sclereids and polymorphic sclereids in the form of osteosclereids, dendroid or steUate sclereids in 14 species of the genus Linociera (Rao, 1950 a, 1957 b) and trichosclereids in 7 species of the genus Scindapsus (Rao, 1964). Bokhari and Burtt (1970) working on sclereids of Cyrtandra eategorised 7 types of sclereids; vermiform, osteosclereids, vesicular, astrosclereids, polymorphic sclereids, dendrosclereids and tracheoids. Rao and Das (1968) have recorded in a few species of the genus Limonium two types of sclereids: filiform and fusiform types showing distinct patterns of distribution of significant morphological interest. Bokhari (1970) has descn'bed in the genus Limonium 4 types of sclereids: vesicular, spindle-shaped, poly- morphie form: osteo to astro type and filiform sclereids. Nicolson (1960) reeognised trichosclereids in the genera Pothos, Scindapsus and t~haphidophora. Singh (1968) recognised 2 types: Linear type and H-type in a few species of the genera Scindapsus and Rhaphidophora. Rao and Wee (1966) working on foliar sclereids in 8 genera and 9 species belonging to Annonaceae and Myristicaceae have recognised three main types of sclereids: filiform, stellate and columnar. Paliwal and Kakkar (1970) have described three types of sclereids: filiform, stellate-polymorphic and brachysclereids in the laminae of five species of Garrya of Garryaceae.

In view of the introduction of varied descriptive terms from time to time an attempt has been made in the present study to classify them into Typology oJ Sclereids 43 distinct categories with a view to enhance their utility as distinct morphological types, in detailed descriptions of sclereids.

SCLEREID TYPES AND CLASSIFICATION Depending on the constancy of the body shape the sclereids may be classified into two main sub-divisions: Monomorphic and Polymorphic. In the first, sclereids have a uniform simple base form with even or uneven or lobed outline, normally these do not show branching processes and even when they are there they do not change the body shape. In the second, sclereids have extreme complex base forms with uneven outline and con- stantly show regular branching leading to symmetrical or asymmetrical body shape.

MONOMORPHIC SCLEREIDS A further sub-division is based on the outline of the base form in the mature stage: simple, even or lobed and simple with or without a tendency to branch. In the first category three distinct types are included: spheroidal- sclereid, vesiculose sclereid and vermiform sclereid; in the second, four distinct types: palosclereids, osteosclereid, fusiform sclereids and filiform. All the types of monomorphic (Figs. 1-23) and polymorphic sclereids (Figs. 24 43) are shown diagrammatically. The salient and distinguishing features of monomorphic sclereid types are mentioned below:

1. Spheroidal Sclereid (Figs. 1-7) This type, also known as stone cells (Schumann, 1889; Warming-Johnsen, 1909), grit cells (Eames and Mac Daniels, 1947) and brachysclereids (Tschirch, 1889), is characterized by simple base forms. Usually, it is spheroidalt globoid or orb~eulate, pyriform or turbinate cell forms. It has been reported in almost all the vegetative and floral parts of several taxa. Their abundance is observed in roots and stems especially in the cortex or pith region. Turbi- nate base form is reported in a few species of Capparis (Rao and Mody, 1961), pyriform base form is observed in Linociera lyzonica L. (Bhupal, 1971). They may be observed as solitary idioblast or may lie loosely together in the form of concretions, nests or ' sclerocysts' (Rao, 1957 a) or agglomerate sclereids (Govindarajalu and Parameswaran, 1967). Under this category one can recognise two types of variations confined mainly to the thickness of the wall layers. In the first, sclereids have a thin wall with a wide lumen and in the 44 T. ANANDA RAO AND O. P. BHUPAL second, they have a thick wall, often striated with a narrow or occluded lumen.

l16 2~

2C I Typology of Sclereids 45

2. VesiculoseSclereid (Figs. 8-11) The term is proposed by Rao (1949) to a simple lobed sac-like base form. Usually it has uneven outline, thin wall with a broad lumen or rarely in a few forms the cell wall is thickened with a narrow lumen. This type of sclereid is reported in Leucospermum conocarpum R. Br. (Rao, 1950 b), a few species of Loranthus (Rao, 1951 a), Schrebera swietenioides Roxb. (Rao, 1949), Linociera glomerata Poh! and Heptacyclum zenkeri Engl. (Solereder, 1908) and Cyrtandra horizontalis L. (Bokhari and Burtt, 1970). 3. Vermiform sclereid (Figs. 12-15) Bokhari and Burtt (1970) proposed this term for the simple cylindrical or tubular base form with rounded ends. It has a thin cell wall with distinct pores and lumen of uniform width. This type is exemplified ;n Cyrtandra elatostemoides Elmer, C. quinquenotata Kraenzlin (Bokhari and Burtt, I970) and also in Linostoma pauciflorum Griff. and L. persimile Craib. of Thymelaeaceae (Rao and Bhupal, 1972); a few sclereids of this type display sigmoid or aUantoid shape. 4. Palosclereids (Fig. 16) The term is introduced by Richter (1920). It is a macrosclereid sensu Tschrich (1889) situated in the palisade parenchyma. The cell forms may or may not have the size and shape of the adjoining cells but they have slightly thickened or rarely thick striated walls, broad lumen and of the same height as the surrounding palisade cells and appear-rectangular in cross-section. They are formed in rows or in isolation. Typical palosclereids are reported in Nyctanthes arbor-tristis L. of Oleaceae (Rao, 1947) and in a few species of Ruyschia, Souroubea and Norantea of Marcgraviaceae (De Roon, 1967), Freziera undulata Sw. of Theaceae (Solereder, 1908; Fig. 29 B, Metcalfe and Chalk, 1957; Fig. 44B) and Diospyros discolor Willd. (Rao, 1951 b) of Ebenaceae, where the sclereid is a transformed spongy cell occupying a palisade disposition.

5. Osteosclereids (Fig. 17) The term was introduced by Tschirch (1889) to bone-shaped cells. It extends into the mesophyll in the form of a column, sometimes touching both the epidermal layers. This base form exhibits thick striated cell wail with a lumen of uniform or irregular width. The ends are flattened or rounded with a slight depression resembling a typical bone-shaped rod. Osteo- selereids are reported in a few species of the genus Camellia (Tschirch, 1889) 46 T. ANANDA RAO AND O. P. BIIUPAL Figs. 348, Barua and Wright, 1959; Figs. 1-8, 11); Gordonia lasianthus L. (Beauvisage, 1920), G. obtusa Wall (Rao, 1951 a); Lacathea pubescens L'Her (Beauvisage, 1920; Fig. 52); Schima noroanhoe Reinw (Beauvisage, 1920; Fig. 46), S. wailichii (Rao, 1953); Nyssa caroliniana Poir. (Solereder, 1908; Fig. 99 A; Metcalfe and Chalk, 1957; Fig. 24B), N. capitata Walt, N. javanica (B1.) Wang and N. sinensis Oliv. (Fam. Nyssaceae) (Rao and Mody, in press); Hakea suavelons R. Br. (Fam. Proteaceae) (Tschirch, 1881; Fig. 23); Popowiapisocarpa (B1.) Endl. (Fam. Annonaceae) (Rao and Wee, 1966); Mouriria cauliflora DC., M. pusa Gards., M. huberi Cogn. (Foster, 1946, Figs. 35 and 37) and Memecylon cuneatum Thw. (Fam. Melastomataceae) (Rao, 1957 a; Fig. 35); Marcgravia browneri (Tr. et PI.) Kr et Urh, M. gouda- tiana (Tr. et PI. de Roon) (Fam. Marcgraviaceae) (De Roon, 1967) and the Cyrtandra bracheia, B. L. Burtt and C. adnata B. L. Burtt (Fam. Gesneeriaceae) (Bokhari and Burtt, 1970) and in Hamamelis mollis Oliv. Eustigma oblongifolium Gard. et Champ, Rhodoleia championi Hook, f. R. ovalifolia Ridl., R. subcordata Exell, R. teysmanni Miq. of Hamamelidaceae (Bhupal and Kundu, 1971).

6. Fusiform sclereid (Figs. 18-21) This type is referred to a short spindle or rod.like base form truncated both ways from a swollen middle portion. Under this category, Foster (1946) has recognised different variants based on the branch system in a few species of Mouriri. Further, he has observed in both the fusiform and branched variants, the ultimate ends of the cell body or its arms are blunt rather than acute. The sclereid wall is thick, striated, pitted and lumen is more or less uniform. They are reported to occur as solitary idioblasts or grouped in twos or threes in a few species of Mouriri (Foster, 1946), Memecylon (Rao, 1957), Linociera (Rao, 1950 a, 1957 b), Limonium (Rao and Das, 1968 ; Boldaati, 1970), Scindapsus (Rao, 1964), and Rhaphidophora where the linear type sensu Singh (1968) corresponds to the fusiform sclereids. Sometimes they group together to form a ' sclerocyst" as recorded in a few species of Limonium of Plumbaginaceae (Rao and Das, 1968) or more or less intimately grouped to form regular strands along the lateral margins of the leaves of Maba nigrascens of Ebena,~eae (Rao and Kelkal, 1951), Exbucklandiapopulnea (R. Br. ex. Griff.) R. W. Brown of Hamamelidaceae (Rao, 1968) and certain members of Myrsineae (Heberlandt, 1914). In the present study they are present in Disanthus cercidifolium Maxim. and Hamamalis mollis Oliv. of Hamamelidaceae, Linociera ramiflora (Roxb.) Wall., L. macrophylla Wall. of Oleaceae. Typology of Sclereids 4?

TExT-FIns. 24-43 7. FtTiform sclereid (Figs. 22--23) This term is adopted by Foster (1946) to a series of slender greatly ©longated accuminate fiber-like cells which are bent or twisted to various 48 T. ANANDA RAO AND O. P. BHUPAL degrees. Often they are found penetrating into the mesophyll in the most varied directions and extend beneath the epidermal layers. Sometimes they fork at one or both ends. They are reported in a few species of Mouriri (Foster, 1946), 82 species of Memecylon (Rao, 1957 a), 13 more species of Memecylon (Bhupal, 1971), in 17 species of Olea(Rao, 1948; Bhupal, 1971) 2 species of Ligustrum (Rao, 1953) and 13 species of Linociera (Rao, 1950 a, 1957b and Bhupal 1971), Gymnacranther~ forbesii (King.) Warb. of Myristacaceae, Cyathocalyx ramuliflorus J. Sinclair, Desmos dasyma- scl,alus and Phaeanthus ophthalmicus J. Sinclair of Annonaceae (Rao and Wee, 1966).

POLYMORPHIC SCLEREIDS Under this category is included a heterogeneous assemblage of extreme base forms varying in their body shape and mode of branching. In a broad sense they are grouped under four main categories : ramiform gclereids, astrosclereids, polyramous sclereids and idiofibrosclereids. Each category conforms to one base form from which the other deviations can be traced. 1. Ramiform sclereid The term is applicable to columnar base forms having ramifying ends. Under this cateogry 2 types of sclereids are recognised: Rhizosclereid and I-shaped sclereids and their variants. The salient features of the above types are as follows: Type (i) Rhizosclereid (Figs. 24-26).--The term proposed by Richter (1920) to such base forms which are more or less similar to palosclereids in shaPe and position but diffe~ from them in possessing root-like branches towards the spongy cells and sometimes possess intraepidermal branches running parallel to epidermal layers or drooping down towards the palisade cell. The short or long columnar mainbody with rooting ends constitute the characteristic feature of this sclereid. Such types may be found disposed in any part of the mesophyll. This type of sclereid is reported in a few species of Niebuhria DC. of Capparaceae (Rao, 1958 ; Figs. 10-11); Ruyschia, Souroubea and Norantea of Marcgraviaceae (De Roon.. 1967); Adinandra jackiana Korth. and A. dumosa Jacq. of Theaceae (Beauvisage, 1920; Figs. 21 and 23), Cleyera grandifloraHook, f. et Thorns (Solereder, 1908; Figs. 29 C and D; Metcalfe and Chalk, 1950; Figs. 44 C and D) and Diospyros discolor Willd. of Ebenaceae (Rao, 1951 b). In the present study they are recorded in Eustigma oblongifolium Gard et Champ. of Hamamelidaceae, Typology of Sclereids 49

Type (ii) 1-shaped selereid (Figs. 27-29).--This type and its variants have a columnar body and exhibit interepidermal branchings of limited or extended length at the poles. They resemble typical I-girders as reported in Mouriri pusa Gardn. (Foster, 1946) and sometimes exhibit slight swelling in the midcolumn and also develop branches in the form of anchors as observed in Memecylon seutellatum (Lour) Naud (Rao, 1957 a; Fig. 34) and also in a few specimen of Fagraea (Singh, 1967). When the intraepidermal branching is confined to one pole, the result- ing body is T-shaped Y-shaped as recorded in species of Olea (Arzee, 1953 a; Rao and Kulkarni, 1952) and a few species of Fagraea (Singh, 1967). The presence of I-shaped sclereids alternating with osteosclereids has been reported in Memecylon cuneatum Thw. (Rao, 1957 a; Fig. 35). Columnar branched sclereids are reported in Mouriria cauliflora DC. and M. abnormis Naud. (Foster, 1946) and also in Olea dioica Roxb. (Rao and Kulkarni, 1952) where the branch systems have extensive development. In the present study similar

TABLE I Chart showing the sclereid types with the original term proposed by Tsehirch (1889)

Categories of sclereids MONOMORPHICBASE POLYMORPHICBASE proposed by FORM FORM Tschirch (1889)

(SPHEROIDAL SCLEREIDS BRACHYSCLEREIOS {VESICULOSESCLEREIDS (VERMIFORM SCLEREIOS f RHIZOSCLEREIDS OSTEOSCLEREIDS OSTEOSCLEREIDS RAMIFORM IT-Shape SCLEREIDS SPALOSCLEREIDS SCLEREIDS MACROSCLEREIDS ~FUSIFORM SCLEREIDS i I-Shape SCLEREmS t. Y-Shape SCLE~mS (OPHIUROSCLEREIDS ASTROSCLEREIDS PUR~ STELLATE ASTRO- ~TRICHOSCLEREIDS FORMS SCLEREIDS (LIBROSCLEREIDS

FILIFORM SCLEREIDS POLYRAMOUSSCLEREIDS (Bizarre SHAPE) IDIOFIBROSCLEREIDS 50 T. ANANVA RAO ANt> O. P. BHUPAL

cell forms are observed in Osmanthus fragrans Lour. and also by Gritfith (1968).

2. Astrosclereids (Figs. 30-31) The term as used by Tschirch (•889) in a broad sense/s applicable to cell forms showing a good deal of diversity. This represents a large heterogeneous assemblage of sclereids having shorter or longer radiating branches. In view of the introduction of a few new descriptive terms for other forms of astrosclereids it is proposed to apply the term only to typical stellate forms. A typical astrosclereid has a thickened central part; small to wide lumen with number of arms of comparatively short length radiating in all directions. In all reported cases, the astrosclereids conform more or less to the typical cell form as described above but this type is invariably modified by possessing an increase in the length of the radiating arms and falls into next category of sclereids: ophiurosclereids, librosclereids and trichosclereids. Type (i) Ophiurosclereid (Figs. 32, 33).--This is nothing but a specia- lized form of astrosclereid. The sclereid in this case has a short central lumen, thick striated wall and displays long drawn out arms, sometimes laying parallel to the surface of the leaf. The extended arms are of varied length and sometimes the elongated arms extend in opposite directions. Johnsson (1880) introduced the above terminology in his study on the leaf anatomy of the Proteaceae. Richter (1920) has adopted this term in his study of the family of the Marcgraviaceae. Further its utility is shown by De Roon (1967) in his detailed studies on the foriar sclereids in the Marcgraviaceae. Type (ii) Librosclereids (Figs. 34-36).--The term introduced by Richter (1920) to such type of astrosclereids which have elongated arms extending in opposite directions and reduced to four, three or two in numbers. The typical ribrosclereid is said to posses a small central part, with two small arms and two very long arms extending in opposite direction almost resem- bring a fibre. This type of fibre-rike sclereids are reported in the stem and leaves of many species of Marcgraviaceae (De Roon, 1967), Pelliciera rhizophorae Tr. et P1. of Pelliceriae (Solereder, 1908; Beauvisage, 1920) and many species of Scindapsus and Rhaphidophora of Araceae (van Tieghem, 1866; Richter, 1899; Bloch, 1946; Nicolson, 1960; Rao, 1964; Singh, 1968 and Bhupal, 1971). Type (iii) Trichosclereid (Figs. 37, 38).mThis base form is one in which 4 arms are found extending in opposite direction, showing a strikin~ Typology of Sclereids 51 resemblance to H-shape and always disposed parallel to the surface of the leaf. This type of sclereids is also indicated in the literature as poil interne en 'H' (van Tieghem, 1866, 1891), trichoblast (Sachs, 1882), sclereiden (Francken, 1890), interna! hairs (De Bary, 1884, p. 222), trichosclereids (Bloch, 1946) and H-shaped sclereids (Rao, 1964; Singh, 1968). Recently the term trichosclereid is adopted in the studies on a few taxa of Araeeae (Rao, 1964; Nicolson, 1960). The present study in agreement with the observations of Rao (1964), Nicolson (1960) and Singh (1968) has shown the presence of these cell forms in many species of Scindapsus and Rhaphidophora. In view of its distinct cell form the present work supports the usage of the term ' trichosclereid' as proposed by Bloch (1946) and adopted by subsequent workers. The advantage of retaining this term is two fold. It is non-ambiguous and self-explanatory. H-shaped sclereids can be considered as fibre-shaped sclereids with reservation. The present work holds the view that it is a modification of astrosclereid and strongly supports for the retention of the term ' trichosclereids ' for H-shaped forms.

3. Polyramous Selereids (Figs. 39-42)

This term is proposed to sclereids which differed from one another in shape and branching in one and the same leaf expanse. Richter (1920) introduced the term ' Idiosclereid' to such varied base forms. Tschirch (1889) included such bizarre selereids under the category of astrosclereids. However, De Roon (1967) adopted Richter's term and assigned only pure stellate forms to astrosclereids. Foster sees no justification of separating so-called 'Idio- sclereids' as a district category. On the contrary Rao's (1950 b) term ' poly. morphic sclereids' he considers' seems entirely appropriate. 'Further he says that' in the leaf of Trochodendron it would be clearly impossible to separate typical stellately-branched astrosclereids form so-called' idiosclereids. All idioblastic ramified sclereids vary to some degree in the same population in one leaf, and the p~efix ' idio' (----- strange of peculiar) represents a salient feature common to all bIanched types of sclereids and for this reason is not an explicit term, from morphological viewpoint (Personal communication to Dr. B.C. Kundu). Rao (1957 a) distinguished bizarre forms from the pure stellate forms under the term ' dendroid sclereids' in the cleared lamina of Memecylon spthandra El. Bokhari and Burtt (1970) have reported astro- selereids and dendrosclereids in the mesophyll of Cyrtandra axillaris CI. and only dendrosclereids in C. lambirensis B. L. Burtt. Similar type of dendrosclereids are reported in a few species of Boscia of Capparidaeeae 52 T. ANANDA RAO AND O. P. BHUPAL

(Pestalozzi, 1898). Thus one could see in the studies of the above-mentioned authors an attempt to seggregate pure stellate forms from the other bizarre forms.

4. ldiofibrosclereid (Fig. 43) This term is proposed to extra xylary sclerenchymatous fibres closely associated with veins and veinlets and often leaving the veins to intrude into the adjacent mesophyll (Rao and Bhupal, 1971). This feature in the cleared leaf expanses is reported in various taxa of Angiosperms (Solereder, 1908; Metcalfe and Chalk, 1957). Rao (1960) has investigated the ontogeny and development of similar cells in Manilkara hexandra (Roxb.) Dubard. Structurally, these peculiar fibre like, base forms possess thick cell wall and lumen of irregular width. As a result of irregular branching especially in the mesophyll region they often appear as irregularly shaped sclereids. Recently they are recorded in Cynometra cauliflora L. and C. polyandra Roxb. of Caesalpinoideae; Loropetalurn chinense Oliv., Trichocladus ellipticus E. et K., Distylium indicum Benth., and Sycopsia griffithiana Oliv. of Hamamelidaceae; in Linostoma decandrum (Roxb.) Wall. ex Endl., L. pauciflorum Griff., L. persimile Craib. and Enkleia malaceensis Griff., E. siamensis (Kurz.) Nevling of Thymelaea- ceae (Rao and Bhupal, 1972).

AC KNOWLEDGEMENT

We wish to thank Dr. K. Subramanyam, Director, Botanical Survey of India, for kind encouragement.

REFERENCES

Arzee, Tc~va .. "Morphology and ontogeny of foliar scler~ids in Olea europaea. I. Distribution and ~tructure," Am. J. Bot., 1953 a, 40, 680-81. Barua, P. K. and Wight, W... "Leaf sclereids in the taxonomy of Thea camellas. I. Wilson's and related camellias," Phytomorph., 1959, 8, 257-64. Beauvisage, L. .. "Contribution aletude a~atomique de la famille des Ternstro- emiaeeae," These Poitiera., 1920. Bhupal, O.P. .. "Studies on the foliar sclereids in a few taxa of seed plants," Ph.D. Thesis, University of Calcutta, 1971. .and Kundu, B.C. .. "Systernatics of Rhodoleia," Trans. Bose. Res. Inst., 1969, 32, 31--40. Bloeh, R. .. "Differentiation and patterns in Monstera deliciosa. The idioblastic development of tdchoscleleids in the air root," Am. J. Bot., 1946, 33, 544-51. Typology of Sdereids 53

Bokbari, M.H. .. " Morphology and taxonomic significance of Foliar sclereids in Limonium," Notes Royal Bot. Gard., 1970, 30, 43-54. and Burtt, B.L. .. "Studies in the Geseneriaceae of the old world. XXXII. Foliar sclereids in Cyrtandra," Ibid., 1970, 30, 11-21. De Bary, A. .. Comparative Anatomy of the Vegetative Organs of the Phenerogams and Ferns. English translation by F. O. Bower and D. H. Scott, Clarendon Press, Oxford, 1884. De Roon, A. C. .. " Foliax sclereids in the Marcgraviaceae," Acta bot. Neerl. 1967, 15, 585-623. Fames, A. J. and An Introduction to Plant Anatomy, 2nd Edition, McGraw-Hill MaeDaniels, L. H. Book. Co., New York, 1947. Foster, A. S. .. "Comparative morphology of the foliar sclereids in the genus Mouriria Aubl," J. Arnold Arbo., 1946, 27, 253-72. Franeken, C. J.W. .. Die Sclereiden Dissertation, Utrecht., 1890, Govindaraj du, N. and "On the morphology of th~ foliar sclereido in the Salvadoraceae," Parameshwaran, N. Beifr. Biol. Pflanzen, 1967, 43, 41--47. Gritilth, M. M. .. "The structure and development of fc liar sclereids in Osmathus fragrans L.," Phytomorph., 1968, 189 73-9. Jolmsson, B. .. "Bidrag till Kannedomen on bladete anatomiska byggnod hos Proteaceerna," Lund., 1880. Haberlandt, G. .. PhysiologicalPlant Anatomy, English translation by M. Drummond, London, 1914. Metealfe, C. R. and Chalk, L. Anatomy of Dicotyledons, 1957, (Reptd. ed.) Vols. I & II, Clarendon Press, Oxford. Morley, T. .. "The genus Mouriri (Melastomataceae): a sectional revision based on anatomy and morphology," Univ. Calif. pub. Bot., 1953, 26, 223-312. Nieolson, D.H. .. "The occurrence of Trichosclereids in the Monosteroideae (Aceraceae)," Am. J. Bot., 1960, 47, 598-602. Paliwal, G. S. and Kakkar, L. "Leaf anatomy of some Garrya specks" Bot. Jour. Lin. Soc. 1970, 36, 81-90. Pestalozzi, A. .. Die gattang Boscia. I_am. Bull. deL' Herb. Biossier, 1898, Appendix III. Rao, A. N. and Wee, Y. C... "Foliar sclereids in certain members of Annonaceae and Myristicaceae," Flora B., 1966, 156, 220-31. Rao, T.A. .. "Foliar Sclereids in the Oleaceae---1," J. lndian hot. Soc., 1949, 26, 251-54. "On the occurrence of sclereids in the genus Olea," Sci. & Cult., 13, 299--300. "Studies on foliar sclereids in Dicotyledons. II," J. Bombay Univ., 1959 b, 19, 25-31. "Foliax sclereids in the Oleaceae---II" J. Indian bot. Soe., 1950a, 29, 220-24. 54 T. ANANDA RAO AND O. P. BHUPAL Rao, T. A. .. "Studies on foliar scleroids. A preliminary survey," J. Indian bet. Soc. 1951 a, 30, 28-39. .. "Studies on fcliar s¢lereids in Dicotyledons--l," Prec. lndian Acad. Sci., 1951 a, 34 (B), 92-98. .. "Studies on foliar sclereids in seed plants," Ph.D. Thesis, Mys. Univ., 1953• .. "Comparative morphology and cntogeny of foliar sclereids in seed plants. I. Memecylon L.,'" Phytomorph., 1957 a, 7, 306-30. .. "Comparative morphology and ontogeny of foliar selereids in seed plants, II. Linociera Swartz." Prec. nat. lnst. Sci. India, 1957b, 23 (B), 152-64. .. "Studies on foliar sclereids in Dicotyledons--VI. Origin and development ~f terminal sclereids in the leaf of Niebhuria apetala," Prec. lndian Acad. Sci., 1958, 223-28. .. "On the multi-septate tlichosclereids in tbe genus Scindapsus," Ibid., 59 b, 66-9. .. "Distfibutimaal patteln of seleigids," Curt. Sci., 1968, 37, 358-64. •. "Studies on foliar sclereids in Dicotyledons--VII," Prec, lndian Acad. Sci., 1960, 52, 27-31. .. "On the occurrence of selerosed palisade ceils in the leaf of Nyctanthes arbor-tristis L.," Curr. Sci., 1947, 16, 122-23. and Dakshni, "Systenmtics of Memecylon. A preliminary survey based on K. M. M. the sclereid morphology," IBM., 1963, 58 B, 28-35. ~-- and Das, G. C. .. "Foli0r sclereids in some species of Limonium (Plumbaginaceae), Curr. Sci., 1968, 37, 352-54. and Mody, K.J. .. "On terminal seloreids and tracheoid idioblasts," 1"roe. Indian Acad. Sci., 1961, 55 (B), 257-62. and Kelkar, S.S. .. "Studies on foliar sclereids in Dicotyledons---III," J. Bombay Univ., 1951, 20, 16--20. and Kulkarni, C.Y... "Foliar sclereids in the Oleaceae--ll," 1bid., 1952. 20, 52-57.

and Bhupal, O. P. .. "Typology of foliar sclereids in Thymelaeaceae," Curr. Sci., 1972, 41, 844-86. and ~ .. "Idiofibrosclerelds," 1bid., 1971, 40, 551-52. Richter, A. .. "Adatok a Marcgraviaceae," Termizet. Fuzaetk, 1899, 22) 27-87. .. "Uber einige I ewe Glie der Marcgravnaceen, auf Basie der phylo- genie mad der Vergleichende Anatomie," Math. Naturw. Bevichte Ungarn, 1920, 31, 65-146.

Sachs, J. .. Text Book of Botany, Oxford, 1882. Sinsh, H. •. "Foliar selereids in some species of Raphidophora and Scindapsus," The Gardens Bulletin, Singapore, 1968, 29 (3), 461-67. Typology of Sclereids 5~

Singh, H. .. "S¢lereids in Fagraea, " Ibid., 1967, :12, 193-212. Solereder, H. .. Systematic Anatomy of the Dicotyledons, Vols. I and lI, 1908, Clarendon Press, Oxford. Schumann, C. R. C. .. "Anatomische studien uber die Knospenachuppan Von Coni- feren und Dicotylen Holagewachsen," Bibloi Bot., 1889, 3, 1-32. Tieghem, P. van. .. "Recherches sur la structure des Aroidees," Ann. Sci. Nat., 1866, 5 (6), 72-210. Tschirch, A. •. " Uber ¢inige Beziehungen des anatomischen Baus¢ der Assimila- tionsovgans Zu Klima und Standort, mit spezieller Beruek sichtigung des Spall to flungsaparates," Linnaea, 1881, 43. 139-252. .. Angewandte pflanzanatomie, Wion and Leipzig, 1889 Warming-Johanse .. Lehrbuch der allgeminen Botanik, 1909.