Typology and Taxonomic Value of Foliar Sclereids in the Proteaceae II. <Emphasis Type="Italic">Adenanthos </E

Proc. lndian Acad. Sci. (Plant Sci.), Vol. 93, No. 6, November 1984, pp. 609-620 P¡ in India.

Typology and taxonomic value of foliar sclereids in the Proteaceae IL Adenanthos Labill,

T ANANDA RAO and SWAPNA CHAKRABORTI Botany Department, Bangalore University, Bangalore 560056, India MS receivcd 14 June 1984; revised 24 August 1984 Abstrar A majority of Adenanthos species possess diffuse sclereids. Theyare classified into major types. Their presenceof absence is listed in Netson's re•ised schemeofclassification on this gr to indicate the overall perspective of their use in taxonomy. Further taxonomic problems alluded to by Nelson are i.quminated here by sclereid typology. Keywords. Foliar sclereids; typology; Adenanthos; Proteaceae.

1. Introduction

This genus is endemic to Southern Australia especially in parts with a mediterranean- type climate (Aschamann 1973). The main concentration of species is in South-West and Western Australia, South Australia and Victoria. Recently Adenanthos was revised taxonomically anda new section has been established (Nelson 1978). Notwithstanding the reported occurrence of sclereids in a few species of this genus, there is no detailed study on their typology and taxonomic implications. In ~nany instances the accounts ate inadequate for taxonomic judgement (Jonsson 1879; Solereder 1908; Metcalfe and Chalk 1950; Rao and Bhattacharya 1978; Rao and Das 1979).

2. Materials and methods

The materials for this study were procured from the following herbarium Curators/Directors. These herbaria are listed, following the symbols published by Holmgren et al (1981). Adenanth'os acanthophylla George, Western Australia, Hamelin Port to Tamela, E. C. Nelson 17009 (DBN). A. apiculata R. Br., W. Australia, Moore Dt., E. Pritzel 290 (CAL). A. argyrea Diels ex Diels et Pritz., W. Australia, North of Taxin Rock, P. Sandersons. s.n. (OBN); W. Australia, West of Hyda, J. S. Beard 5767 (PERXH). A. barbigera Lindl, Western Australia, Swan District, E. Pritzel 74 (CAL); W. Australia, Max Koch 1387 (CAL). A. cacomorpha Nelson, Western Australia, 14 miles of sE of Jerramungup, K. Newbey 2979 (PERXH). A. cuneata Labill., Westem Australia, E. Pritzel 201 (CAL); W. Australia, Mueller s. n. (CAL). A. cunninghamª Meisn., W. Australia, Clovardale, B. Kaspiew 71 (CAL). A. cygnorum Diels, W. Australia, J. Harvel 254 (PERTH). A. o'gnorum Diels subsp, cygnorum Diels, W. Australia, North of Turin Road, P. Sanderson s.n. (DBN). A. detmoldii F. Muell., W. Australia, R. D. Royce 3233 (PERfil). A. dobsonii F. Muell., W. Australia, Mount Heler, B. Kaspiew 68 (CAL); W. Australia, South West of Mt. Rogged, A. S. George 7386 (PE~~H). A. drummondii 609 610 T Ananda Rao and Swapna Chakraborti

Meisn., W. Australia, N. W. of Bedshingarra, A. S. George 6723 (PERTH). A. elliptica George, W. Australia, West Barran range, E. Croxford s.n. (DAN); W. Australia, K. Newbey 1451 (PERTH). A. eyrei Nelson, W. Australia, E. C. Nelson ANtJ 17044 (DBN) (type material). A. filifolia Benth., W. Australia, Max Koch 1767 (CAL);W. Australia, Bluff Knott, Stirling range, R. D. Royce 6053 (PERTH). A. flavidiflora F. Muell., W. Australia, slope of East Mount, Barron and Croxford s.n. (CAL,DBN); W. Australia, slope of E. Mount, Barren and Croxford s.n. (DAN); W. Australia, near Commander Rocks, R. A. Jaffery 430 (PERTH). A. forrestii F. Muell. W. Australia, Twilightcave, A. S. Weston 8274 (PEgTH). A. 9labrescens Nelson, subsp, glabrescens Nelson, West Australia, 10 miles SE of Lake King, A. S. George 3653 (PERTH). A. gracilipes George, W. Australia, 6 km or on peak Charles, A. S. George 15106 (PERTH). A. ileticos Nelson, W. Australia, near Red Lake, E. C. Nelson ANU 17007 (DBN). A. labillardierei Nelson, West Australia, Higher slopes of Whoogarup range, A. S. George 1941 (PERfil). A. linearis Meisn., W. Australia, Stirling range, E. Wittwer 600 (PERTH). A. macropodiana Nelson, Bayswater, Lower Swan River, Alex Morrison s.n. (PERfil). A. meisneri Lehm., W. Australia, Dt. Wellington, E. Pritzel 98 (CAL). A. obovata Labill., W. Australia, South-West, E. Pritzel 246 (CAL);W. Australia, Kirrup., E. Pritzel 2074 (CAL). A. oreophila Nelson, East Mt, Barren, G. A. Gardener s.n. (PERTH). A. pungens Meisn., W. Australia Ongarup, K. Newbey 917 (PERTH). A sericea Labill., W. Australia, South-West, E. Pritzel 245 (CAL). A. sericea Labill., subsp, sericea Labill., W. Australia, Albany, P. Sanderson s.n. (DBN). A. sericea, subsp, sphalma Nelson, W. Australia, Thistle cave, Cape le Grand National Park, E. C. Nelson ANU 16591 (CANB). A. sticta A. S. George, W. Australia, C. A. Gardner s.n. (PERTH). A. terminalis R.' Br., W. Australia, Lofty range, B. Kaspiew 147 (CAL). A. venosa Meisn., Barren range, E. Croxford s.n. (DAN); W. Australia, Mount Barren, A. S. George 6976 (PERTH);North of Hameraley R. estuary, A. S. George 7219 (PERTH). A. cuneata x dobsonª Nelson, ANU 17071 (DBN). A. cuneata x forrestii Nelson, ANU 16981 (DBN). A. macropodiana x terminalis Nelson, ANU 17038 (DAN). The clearing technique is after Rao and Naidu (1981), and the sclereids categorised after Rao and Bhupal (1973).

3. Observations

Studies on cleared leaves, transverse sections and macerations of 31 species of Adenanthos revealed that sclereids of different forros are present in all except the following species: A. apiculata R. Br. (E. Pritzel 290, CAL), A. barbigera Lindl. (E. Pritzel 74, CAL), and A. obovata Labill. (E. Pritzel 246, cAL).

3.1 Typology The varied sclereids observed during the study are categorised under the following types with examples.

3.la Spheroidal sclereids: Sclereids conforming to spheroidal to sub-spheroidal forms with a broad lumen and relatively thick striated secondary wall are recorded in A. argyrea Diels (J. S. Beard 5767, PERTH), A. cygnorum Diels subsp, cygnorum (P. Sanderson s. n., DBN), A. dobsonii F. Muell. (A. S. George 7336, PERTH), Foliar sclereids in Proteaceae 611

A. drummondii Meisn. (A. S. George 6723, PERTH)(figures 2, 3), A.flavidiflora F. Muell. (R. A. Jaffrey 430, PERTH), A. forrestii F. Muell. (A. S. Weston 8274, PERTH), A. labillardiereiNelson (A. S. George 1941, PERTr0, A. linearis Meisn. (E. Wittwer 600, PERTH), A. macropodiana Nelson (Alex Morrison s. n., P› A. oreophila Nelson (C. A. Gardner s. n., PERTtt), and A. venosa Meisn. (A. S. George 6976, PERTr0. Sclereids vary from sub-spheroid',d to gnarlyform in A. cygnorum Diels subsp. cygnorum, A. dobsonii and A. flat, idiflora. In a majority of cases, the sclereids have a

Figures I-3, (• Transectiorts of the leaves: I..4. ti/ifolia Benth. (R. D. Royce 6053, PERTH)showing gnarlyformsclereids in the inner palisade region. 2. A. drummondii Meisn, (A. S. George 6723, e~gTJ~)showing spheroidal to sub-spheroidal sclereids in the vicinityof vascular bundles. 3. A. drummondii Mr (A. S. George 6723, eF.RTH).Stylised diagram showing the position of spheroidaI sclereids along the vicinityof velas. 612 T Ananda Rao and Swapna Chakraborti smooth outline, but in A. linearis and A. venosa they show varied lobes of limited size resembling vesiculose sclereids (figure 8).

3. l b Gnarlyform sclereids: They are thick-walled mis-shapen small-sized cell forros with protuberences of irregular shapes and size. They have striated cell wall, narrow or occluded lumina and are found scattered in different parts of the mesophyU. They are observed in A. detmoldii F. MueU. (R. D. Royce 3235, VER'ra), A. dobsonii F. Muell. (A. S. George 7386, t'ERrH), A.filifolia Benth. (R. D. Royce 6053, Pz~rn) (figure 1), A. meisneri Lehm. (P¡ 98, CAL), A. sericea Labill. (Pritzel 245, CAL) and A. terminelia R. Br. (Kaspiew 147, CAL).

3.1c Rhizosclereids: Rooting columnar cell forms with spicule-like branches at one end found in the mesophyrl of A. acanthophylla George (Nelson 17009, OBN) and A. elliptica George (K. Newbey 1451, PERfil; figures 12, 7).

3. I d Palosclereids: Small-sized palisade-like ceU forms with spiculated branches are observed in A. 91abrescens Nelson (A. S. George 3653, PERXH; figure 11).

3. le l:usiform sclereids: These sclereids have a broad mid-portion with fusoid polar ends. Often they are found in rows, and are conspicuous in the mesophyll region. This is exemplified in A. cunninghamai Meisn. (Kaspiew 71, CAL).

3. I f Ramiform sclereids: These sclereids are more or less I-shaped and often with attenuated branches at the ends. They are exemplified in A. cuneata Labill. (Pritze1201, CAL), A. elliptica A. S. George (K. Newbey 1451, PER'fil), A. eyrei Nelson (Nelson ANt0 17044, OBN), A. gracilepis A. S. George (A. S. George 15106, PER'm; figure 4), A. ileticos Nelson (Nelson ANU 17007, DBN), A. pun.qens Meisn. (Newbey 917, PER'rr0 and i

Figure 4. as view of cylindricat leal of A. 9racilipes George (A. S. George 15106, eER~r~) showing ramiform sclereids disposed mostly in the second layer of palisade cells ( • 450). Foliar sclereids in Proteaceae 613

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Figures 5-7. rs of the leal sectors: 5. A. cacomorpha Nelson (K. Newbey 2779. ~'ERTH): Polyramous sclereids disposed mostly in the palisadr laycr ( x 450). 6. A few potyramous sciereids en•argr (x 800). 7. A. elliptica A. S. George (K. Newbey 1451, PEaT~). Rhizosclereids in rov~ along abaxial and adaxia| palisadr layers ( x 450).

A. cuneata • forrestii Nelson tA~qu 16981, Dan). In a[l the above species sclereids are lbund scattered but in A. pungens, they forro a row in the mesophyll.

3. I g Polyramous sclereids: They show distinct multiple branches of irregular size and length. The central portion of the sclereid possesses a big lumen, which is very much obliterated in the arras. This is observed in A. acanthophylla George (Nelson 17009, DBN), A. sticta A. B. George (C. A. Gardner s.n., PErtr~; figure 10), A. cacomorpha Nelson (K. Newbey 3779, t'e~~-H) (figures 5, 6) and A. dobagii Nelson (Nelson A•u 17081, cana). 614 T Ananda Rao and Swapna Chukraborti

,. ~ ~ ~, :., ; ; ' . ; . . ; ',( . ' ~.~---~~-§ !~--,.-.~ ...... ~;.

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Figures 8-10. ( • 450) Ts of the leaf sectors: 8. A. venosa Meisn. {A. S. George 6976, PERTtt); Vesiculose sclereids in the adaxial palisade region. 9. A. Jbrrestii F. Muelt. (A. S. Weston 8274, peR'ra); Sub-spheroidal sclereids in the vicinity of vascular bundles. 10. ,4. sticta A. S, George {C. A. Gardner s.n., pERTn)" Polyramous sclereids in the mesophyll.

4. Shape of leaf and the type of sclereids--A correlation

This genus, displays a very wide variety of leal forros tchart 1 --figures 1-26, after Nelson 1978)2 With this background, the types of sclereids were studied. It was found with a few exceptions (chart I--figures 5, 11) that there is a very intcresting correlation between the type of sclereids and the shape of the leal. Laminar types of leaves, possess ramiform to polyramous sclereids (chart I: figures I-3. 6. 7, 16-i8) whereas Foliar sclereids in Proteaceae 615

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Figures 11, ! 2. ( • 60) TS of the leaf: i !. A. 91abrescenz Nelson (A. S. George 3653, PERTH,I showing palosclereids with short spiculated branches at the end distributed in the second palisade layer. 12. A. ettiptica A. S. George (K. Ne~,,'bey 1451. PErtrla) showing dense disposition of rhizo~lereids in two rows in the mesophyll. Figures 13-15. ( • 60) Cleared sector ofleaf: 13. A.forrestii F. Muell. (A. S. Weston 8274, PERTH) showing spheroidal sclereids in the vicinity of the main vein. 14. A, filifolia (R. D. Royce 6055, PEarH) showing sclereids at the vicinity of the veins. 15. A. oreophila NeLson (C. A. Gardner s.n,, rER'rH) showing sub-spheroidal sclereids around the veins.

segrnented filiform leaves have spheroidal to gnarlyform sclereids (chart 1: figures 8-10, 12---15, 20--26). This feature may be governed by a number of diverse factors. Detailed ontogenic studies may lead to better understanding of this situatio,1.

P"4 616 T Ananda Rao and Swapna Chakraborti

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Cbart I, Shape ofleaves and the type of sclr in the genus Adenanthos--A correlation (shape of Leaves after Ne|son 1978: scale is given to laminae only: shape of sclereids not to scale), 1. A. cuneata (I-shaped ramiform sclerr 2. A. sticta (polyramous sclereids), 3. A. elliptica (columnar rhizosclereids), 4. A. obot~ata (nil), 5. A venosa (gnarlyform sclerelds), 6. A. acanthoph)'lla (rhtzoscLereids). 7, A. cuneata • forrestii (ramiform Y-shaped sclereids) 8. A. forrestii (spheroidal sclereids), 9. A. dobsonii (gnarlyform sclereids), 10. A. detmoldii (gnarlyform sclereids), 11. A. barbigera (nil), 12. A. macropod~ana (spheroidat s,clereids), 13. A. terminali~" (vesiculose scleretds). 14, A, flat, idi.[Iora (spheroidal sclcreids), 1:5. ,4. meisneri (gnarlyform sclcretds). 16. A, pun~1ert~" (l-shalxxl ramiform sr 17. A. L3racilipes (ramiform sclereids) 18. A. cunninyhwnii (fusiform sclereids). 19. A. apiculara (nil). 20. A. filiJblia (gnarlyform ~lereids). 21. A, cyclnorum subsp, cyynorum Diels (spheroidal sclereids) 22. A. oreophilu (spheroidal sclereids), 23, 24. A. seri~eu subsp sericea ignarlyform sclereids) 26. A. sertcea subsp, sericea (gnarlyform sclereids). Foliar sclereids in Proteaceae 617

5. Systematie applicability

The earliest treatment on Adenanthos is that of Bentham (1870), In this concise account, he has recognised two sections, namely, Eurylaema and Stenolaema. Under this framework, he recognised 14 species. Since then no attempt was made to revise the genus taxonomicaUy, despite the descriptions of a few more species. Recently, Nelson (1978) based on field population studies has published a useful taxonomical revision of this genus. In this account he has recognised two sections: Eurylaema corresponding to Eurylaema of Bentham and Adenanthos with its two sub-sections Anaclastos and Adenanthos corresponding to Stenolaema of Bentham. Following Nelson's classification ofthis genus, an attempt has been made to sort out the varied types of sclereids as discovered in the present work to see how far their presence or absence is helpful in understanding their grouping under different sections.

Taxa Typology of sclereids

Section 1: Eurylaema 1. A. detmoldii F. Muell. Gnarlyform --infrequent]y present. 2. A. barbioera Lindl. Devoid of sclereids 3. A. obovata Labill. --do--- Section 2: Adenanthos Sub-Sr Anaclastos 4. A. drummondii Meisn. (figures 2, 3) SpheroidaI 5. A. doba#¡ Nelson Polyramous 6. A. apiculata R. Br. Devoid of sclereids Sub-Sr Adenanthos 7. A. linearis Meisn~ Spheroidal 8. A. venosa Meisn. (figure 8) Vesiculose 9. A. elliptica George (figures 7, 12) Rhizoform 10. A. olabrescens Nelson (figure II) Paloform I I. A. d~bsonii F. Muell. Gnarlyform 12. A. pungena Meisn. Ramiform 13. A. oracilipes C_reorge(figure 4) Ramiform 14. A. cunninohamª Meisn. Fusiform 15. A. eyrei Nelson Ramiform 16. A. forrestii F. Muell. (figures 9, 13) Sub-spheroidal 17. A. meisneri Lehm. Gnarlyform 18. ,4. cygnorum Diels Sub-spheroidal 19. A. argyrea Diels Spheroidal thick-waUed 20. A. oreophila Nelson (figure 15) Sub-spheroidal 21. A. terminalis R. Br. Gnarlyform 22. A.flavidiflora F. MueU. Sub-spheroidal 23. A, sericea Labill. Gnarlyform 24. A. mascropodiana Nelson Spheroidal (in the vicinity of midrib) 25. A. filifolia Benth. Gnarlyform 26. A. labillardiarai Nelson Spheroidal (in the vicinity of midrib) 27. A. acanthophyUa George Rhizoform 28. A. ileticos Nelson Ramiform 29. A. cacomorpha Nelson (figures 5, 6) Polyramous 30. A. cuneata Labill. Ramiform 31. A. sticla George (figure 10) Polyramous

!'~ 618 T Ananda Rao and Swapna Chakraborti

In the above table one could observe the clear morphological trends of the occurrence of varied sclereid types. In the first trend the mesophyll of a few species Ÿ devoid of sclereids. In the next trend the mesophyll possesses diffuse spheroidal sclereids. The next trend is the presence of gnarlyform sclereids. These crooked, mis- shapen sclereids are very conspicuous in the mesophyll. Lastly, the sclereids of fusiform, ramiform or polyramous types have been encountered.

6. Taxonomic implications Taxonomic probtems alluded to by Nelson (1978) are illuminated here by sclereid typology. Among the three species, namely, A. detmoldii, A. barbigera and A. obovata under Section 1 Eurylaema, sclereids are observed only in A. detmold¡ whereas in the other two species the mesophyll is devoid of sclereids. Nelson (1978) distinguishes A. detmoldii from other members ofthis section, namely A. barbioera and A. obo~'ata in the presence of yeUowish orange perianth, tuberculate foliar glands and segmented juvenile foliage. The present study reveals that gnarlyform sclereids also forro a helpful diagnostic character to distinguish this species. Further, Nelson's conclusion that A. barbigera and A. obovata are closely related and similar is further strengthened by the absence of sclereids in the mesophyll of both the species. Among the three species, namely A. drummondii, A. doba~lii and A. apiculata included under the sub-section Anaclastos of w Adenanthos, spheroidal sclereids have been recorded only in A. drummondii. Thus, the presence of spheroidal sclereids in the vicinity of midrib coupted with other characters like shape of the perianth, arcuate style, tufts of hairs at the throat, as pointed out by Nelson (1978 p. 384) suggest that A. drummondii Meisn. is a distinct species. Further, Nelson is of the opinion that A. dobagii is similar in appearance to the closely related A. apiculata as well as to A.flavidiflora. The present study has revealed that A. apiculata is devoid of sclereids while A.flavidiflora has sub-spheroidal sclereids, and A. doba#ii has polyramous sclereids. These features are sufficient to uphold that they are distinct species. Bentham (1870) considered A. drurnmondii to be a synonym of A. apiculata. However, Nelson (1978) reported that they are quite distinct morphologically and geographically. This viewpoint is further supported by the recorded occurrence of spheroidal sclereids in A. drummondii and their absence in A. apiculata. Section 2. Sub-Sect. Adenanthos Under this sub-section, all the 25 species have sclereids of one type or the other. Further, their diversity, however, provides good diagnostic value in conjunction with the other exomorphic characters. This is illustrated as below: In the leaf forro A. linearis resembles A. glabrescens but in the latter species, the leaves are shorter and broader (Nelson 1978). Similarly, the sclereids of A. linearis ate of spheroidal type whereas they are mostly palosclereids in A. glabrascens. A. r'enosa and A. meisneri possess an indumentum containing glandular hairs. A. venosa has entire leaves and vesiculose sclereids while leaves of the latter species have terete laciniae and gnarlyform sr Nelson is of the opinion that A. elliptica has affinities with A. cuneata and A. sticta but it is easily distinguished from both the species. The sclereidat types in alt the three species are not very helpful at diagnostic level. However, in conjunction with other Foliar sclereids in Proteaceae 619 characters such as flabellate leaves and polyramous sclereids of A. sticta, elliptic leaves and ramiform sclereids in A. elliptica and flagellate or rarely elliptical tomentose leaves and ramiform sclereids ofA. cuneata could be considered ofsufficient diagnostic value. In A. glabrescens although leaves are similar in appearance to A. linearis the sclereidal differences in these species outweigh their similarities. In A. glabrascens, sclereids are paloform whereas in A. linearis they are spheroidal. The presence of dissimilar sclereids, does not support Nelson's (1978) contention that A. glabrescens is closely related to A. dobsonii. George (1974) considered A. gracilipes to be related to A. apiculata. However, Nelson (1978) opined that the two species differ in many aspects, most significantly in the size and morphology of the perianth. Similarly they differ from each other in presence and absence of sclereids in the mesophyll. A. pungens and A. gracilipes have densely sclereified leaves and also similar ramiform sclereids, A. meisneri is distinguished from all other species except A. venosa. However, the presence of gnarlyform sclereids in both the species de,es not facilitate their identiIication. For a long time, A. sericea and A. cygnorum have been confused and some workers regarded A. cygnorum asa variety ofA. sericea (Ewart 1907). However, the two species differ not only in their morphological details (Nelson 1978) but also in having dissimilar types of sclereids: gnarlyform in A. sericea and sub-spheroidal in A. cygnorum. A. ar#yrae is related to A.flavidiflora but it is distinguished by the very small usually trisegmented leaves (Nelson 1978). Both the species, however, have similar types of spheroidal sclereids. A. oreophila was earlier considered to be a form of A. sericea. However, they ate distinct, especially in leafmorphology and anatomy, though the flowers of the two taxa are almost identical. Further, the varied types of sclereids, namely sub-spheroidal in A. oreophila and gnarlyform in A. sericea are distinct features of diagnostic interest in these taxa. A. terminalis is distinguished from A. macropodiana in having less divided leaves, a smaller perianth that is cream-green in colour and by the villous style (Nelson 1978). It is observed that A. terminalia possesses gnarlyform sclereids while in A. macropodiana they are sub-spheroidal in the vicinity of midrib. A.filifolia is closely related to A. labillardierei from which it may be distinguished by the colour of the perianth, the shape of the perianth limb, and the shape of the bracts (Nelson 1978). Further, the above taxa can be distinguished by different types of sclereids in their mesophyll: gnarlyform in A.filifolia and spheroidal in the vicinity of midrib in A. labillardierei. A. acanthophylla does not appear to be closely related to A. cygnorum (Nelson 1978). It is also seen that sclereids are polymorphic in A. acanthophyUa, while in A. cygnorum they are sub-spheroidal. Nelson (1978) considered A. flavidiflora, A. cuneata and A. cacomorpha to be sympatric. Similar types of sclereids, namely ramiform type, are present in A. cacomorpha and A. cuneata but in A.flavidiflora the sclereids are gnarlyform type. Nelson (1978) considered A. cuneata as closely related to A. sticta. However, A. cuneata has ramiform sclereids while A. sticta has polyramous sclereids. The present results lead us to the conclusion that the presence of similar sclereids in a few species of the genus is diagnostically oflimited value at species level but may well be 620 T Ananda Rao and Swapna Chakraborti of taxonomic value at the sectional or genus levei. On the other hand, the presence of varied types of sclereids is a helpful adjunct in establishing the identity of the species. Parallel instances are found in many investigated sclereid bearing genera of the flowe¡ plants (Rao 1980).

Acknowledgements

The authors express their gratitude to the authorities of several herbaria for the gift of leal specimens. They are most grateful to Dr E C Nelson for sending a few critical specimens and to the uc,c, New Delhi for financial help.

References

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