7 Egypt. J. Bot. Vol. 50, pp (2010)

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1 7 Egypt. J. Bot. Vol. 50, pp (2010) Pollen Morphology of Sterculiaceae (s.str.) in Egypt and its Taxonomic Significance R. Hamdy* and E. Shamso Botany Department, Faculty of Science, Cairo University, Giza, Egypt. P OLLEN morphology of 20 species representing 12 genera of cultivated and wild Sterculiaceae in Egypt were examined by light microscope (LM) and scanning electron microscope (SEM) on the bases of differential correlation of aperture type, exine sculpture, size and other characters. Four major types and seven pollen subtypes were recognized: Dombeya type trizonoporate, exine echinate (Dombeya subtype A, interspinal area granulate and Dombeya subtype B, interspinal area foveolate); Abroma type trizonobrevicolpate, exine reticulate perforate; Waltheria type tetra to penta zonocolporate, exine reticulate perforate (Waltheria subtype A, colpi fusiform with lalongate ora and Waltheria subtype B, colpi oblong with subcircular ora) and Brachychiton type trizonocolporate, exine reticulate (Brachychiton subtype A, pollen small, polar axis less than 18.2 µm and Brachychiton subtype B & C, pollen medium, polar axis ranged from µm). The pollen results are discussed with reference to current systematic treatment of Sterculiaceae. Keywords: Aperture type, Egypt, Pollen morphology, Pollen types, Sterculiaceae, Systematic treatment. Sterculiaceae is a sub-cosmopolitan family of genera and 1500 species of trees and shrubs, herbs or lianes. Taxa are mainly distributed in tropical and subtropical regions with few species in temperate zones (Huxley et al., 1992 & Mabberley, 1997). It is represented in the flora of Egypt by 21 cultivated and wild species belonging to 12 genera, 6 tribes and 3 subfamilies (Shamso & Hamdy 2010). The relationships within Sterculiaceae have been discussed for a long time; various authors discussed a relationship of the family to order Malvales and treated it as a separate family (Bentham 1862, Schumann 1890, Edlin 1935, Melchior 1964, Cronquist 1988, Dahlgren 1989 and Takhtajan1997). Within the recircumscribed monophyletic order Malvales, Judd & Manchster (1997), Bayer et al. (1999) and Bayer & Kubitzki (2003) and APG II (2003) merged Sterculiaceae, Tiliaceae, Bombacaceae with Malvaceae and subdivided the enlarged family Malvaceae into nine subfamilies based on molecular, morphological and biogeographical data. *Corresponding author : rimhamdy@yahoo.com & e.shamso@yahoo.com

2 104 R. HAMDY AND E. SHAMSO Pollen morphology of Sterculiaceae has been investigated by various authors (Wodehouse 1935, Selling 1947, Rao 1950, Erdtman 1952, Ikuse 1956, Chaudhuri & Mallik 1965, Litchfield 1966, Sharma 1967, Cristobal 1968, Robyns et al. 1977, Moore et al. 1991, Lakshmi 2003, El Husseini 2006 and Perveen & Qaiser Concerning the studies on pollen morphology among the taxa of the family, Erdtman (1952) distinguished eight pollen types. Sharma (1967) studied 103 Indian species belonging to 22 genera based on aperture and exine sculpture, he recognized 40 pollen types and discussed the taxonomy and evolutionary trends within the family. On order level Lakshmi (2003) described pollen grains of 27 species of Sterculiaceae, while dealing with the pollen morphological studies of the Indian families of order Malvales and his study revealed that the family is highly europalynous with different apertural types. El Husseini (2006) studied 4 Egyptian wild species of Sterculiaceae and recorded two pollen types; she also discussed the relations of Sterculiaceae and Tiliaceae to Malvaceae in the light of palynological findigs by Saad (1960) and Hosni & Araffa (1999). Perveen & Qaiser (2009) studied pollen morphology of 2 species of the subfamily Dombeyoideae from Pakistan; they used the length of polar axis to recognize 2 distinct pollen types. The main objectives of the present work is to investigate and describe the pollen of wild and cultivated taxa of Sterculiaceae in Egypt, and to discuss the results obtained with recent classifications of the family. Material and Methods Pollen samples of 20 wild and cultivated species representing 12 genera were removed from herbarium specimens kept in Cairo University Herbarium (CAI) and the Agricultural Research Centre, Flora and Phytotaxonomy Herbarium (CAIM), as well as fresh specimens grown in various botanical gardens (see Table 1). All materials were taken from mature anthers of flowering buds. List of specimens investigated is in accordance with the system of Cheek (2007); nomenclature of the wild species was updated according to Boulos (2000 & 2009). Voucher specimens and pollen slides were kept in Cairo University Herbarium (CAI). Materials for light microscopy (LM) were boiled for a few minutes in water, macerated in a few drops of an aqueous 10% solution of KOH on a clean slide, then stained with Safranin (1% Safranin solution in 50 % ethanol), mounted in glycerin jelly and observations were made with a Serico research microscope under (E 40, 0.65) using a 16 x eye piece, with an attached Camera, Canon power shot A 95 (12 x). For SEM studies, acetolyzed pollen grains were dusted onto stubs using double sided cellotape, coated with gold and examined by Jeol JXA A Scanning electron microscope operated at an accelerating voltage of 15 KV at Electron Microscope Unit, National Research Center, Dokki, Egypt.

3 POLLEN MORPHOLOGY OF STERCULIACEAE IN EGYPT 105 All measurements are based on at least pollen grains for each specimen, various pollen characters viz: shape, size, aperture type and exine sculpture were determined. TABLE 1. Collection data of the investigated taxa of family Sterculiaceae (The wild native species are preceded by an asterisk). species Localities Dombeyoideae (or Dombeyaceae) 1.1 Dombeya burgessiae Gerr ex Harv. Barrage Medicinal garden, Qaliubiya,, ; V. Täckholm s.n. (CAI)- Orman garden, Giza, ; R. Hamdy s.n. (CAI) 1.2 Dombeya tiliacea (Endl.) Planch. Orman garden, Giza, ; Fawzi & Magida s.n. (CAIM) *2.1 Melhania denhamii R.Br. W. Aideib, G.Elba, ; Shabetai 2762 (CAIM) - W. Laseitit, G.Elba, ; V. Täckholm et al. s.n. (CAI). *2.2.Melhania phillipsiae Baker f. G. Karam, Elba, ; V.Täckholm et al. s.n. (CAI). 3.1 Pterospermum acerifolium (L.) Willd. North garden, El Saff, ; V.Täckholm s.n. (CAI) - Botanical Island, Aswan, ; M. El Mahdi s.n. (CAI). Byttnerioideae (or Byttneriaceae) Tribe I: Byttnerieae 4.1 Abroma augustum (L.) J. A. Murray Agricultural Museum gardens, Dokki, ; Mahdy s.n. (CAIM). Tribe II: Hermannieae *5.1 Hermannia modesta (Ehrenb.) Mast. Wadi Aideib, G.Elba, ; Shabetai F. 1061(CAIM)- S.E. G. Elba, ; G.Täckholm s.n. (CAI). 5.2 Hermannia cuneifolia Jacq. Agricultural Museum gardens, Dokki, ; Khattab No. 27, G (CAIM). *6.1 Waltheria indica L. Wadi Aideib, G.Elba, ; Drar 150/36 (CAIM) - G. Ekwal, G. Elba, S.E. desert, ; Shabetai 2764 (CAIM). Tribe III: Theobromeae 7.1 Glososstemon bruguieri Desf. Fac. of Pharmacy, Cairo Univ, ; El Mahdi.s.n. (CAI)-Agricultural Museum gardens, Dokki, ; Khattab s.n. (CAIM). 8.1 Guazuma ulmifolia Lam. Orman garden, Giza, ; V. Täckholm s.n.(cai) - Botanical Island, Aswan, ; H. Rafaeel (CAIM) Sterculioideae (or Sterculiaceae s.str.) Tribe IV: Sterculieae 9.1 Sterculia balanghas L. Zoological garden, Giza, ; R.Hamdy s.n. (CAI). 9.2 Sterculia foetida L. Zoological garden, Giza, ; K. Fawzi s.n. (CAIM) 10.1 Brachychiton acerifolius (Cunn.ex G. Don) Macarthur 10.2 Brachychiton australis (Schott & Endl.) A. Terrac Brachychiton populneus (Schott & Endl.) R.Br. Agricultural Museum gardens, Dokki, ; Shabetai & Abdallah, g.1951 (CAIM) - Orman garden, Giza, ; M.El Mahdi s.n.(cai) Orman garden, Giza, ; Labib s.n. (CAI) Orman garden, Giza, ; Hassib s.n. (CAI) - Botanical Island, Aswan, ; H. Rafaeel (CAIM). Orman garden, Giza, ; R. Hamdy s.n. (CAI) 10.4 Brachychiton rupestris (T. Mitch. ex Lindl.) K.Schum Brachychiton discolor C. Moore ex F. Muell. Ezbekieh garden, Cairo, ; Shabetai g.1593 (CAIM)- Alfred Bircher s Northeastern garden, El Saff, ; V.Täckholm & El Sayed s.n.(cai) Firmiana simplex (L.) W. Wight Zoological garden, Giza, ; M. El Mahdi s.n. (CAI) - Botanical Island, Aswan, ; H. Rafaeel (CAIM) Pterygota alata Roxb. Manial palace, Cairo, R. Hamdy s.n. (CAI). The terminology used is a combination of Erdtman (1952); Praglowski & Punt (1973); Praglowski & Raj (1979) and Punt et al. (2007).

4 106 R. HAMDY AND E. SHAMSO Results The palynological data of the investigated species are summarized in Table 2. According to exine sculpture, the pollen grains in the present investigation can be classified into two main groups: A. Echinate group: pollen grains are usually spheroidal, trizonoporate, exine sculpture echinate, this group represented a unique major pollen type known as Dombeya type. B. Reticulate group: pollen grains varied from subspheroidal to prolate, with reticulate exine sculpture. Three major pollen types can be distinguished based on the number and the shape of apertures viz. Abroma, Waltheria and Brachychiton type. Among four major pollen types, seven subtypes were recognized based on the pollen shape and size, colpus shape, exine sculpture and other pollen characters. Description of types Dombeya type Pollen grains 3- zonoporate, vary from spheroidal (in Pterospermum) to oblate spheroidal, large in size, mean polar axis ranges from µm; mean equatorial diameter ranges from µm; pores circular, mean diameter ranges from µm, rimmed and ornamented with 4 5 spines; exine sculpture echinate. This type can be subdivided into two subtypes: Dombeya subtype A (Fig. 1 a & b) : Pollen grains spheroidal ( x µm), echinae ± pillar shaped with indistinct base, µm long, with blunt tips and interspinal area granulated. Specimens examined: Pterospermum acerifolium (L.) Willd. Dombeya subtype B (Fig. 1 c & d) : Pollen grains oblate-spheroidal ( x µm), echinae spine-shaped with bulbous and perforated base, µm long, erect or slightly recurved at the apices, with acute tips and interspinal area foveolate. Specimens examined: Dombeya burgessiae Gerr. Ex Harv., D. tiliacea (Endl.) Planch., Melhania denhamii R. Br. and M. phillipsiae Baker f. Abroma type (Fig. 1 e & f) Pollen grains 3- zonobrevicolpate, oblate spheroidal, mean polar axis µm; mean equatorial diameter µm; colpi shortly oblong; length ranges from µm long; exine sculpture reticulate - perforate. Specimens examined: Abroma augustum (L.) J. A. Murray. Waltheria type Pollen grains 4-5 zonocolporate, vary from oblate-spheroidal to prolate spheroidal; mean polar axis ranges from µm; mean equatorial diameter ranges from µm; colpi fusiform or oblong; length ranges from µm long; exine sculpture reticulate perforate, perforation minute and indistinct. Two subtypes are distinguished as follows:

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9 POLLEN MORPHOLOGY OF STERCULIACEAE IN EGYPT 111 a b c d e f Fig.1. Equatorial view of pollen grains in SEM. a & b: Pterospermum acerifolium (pillar - shaped echinae and granules at interspinal area). c & d: Melhania denhamii (spine- shaped echinae and foveolate at interspinal area). e & f: Abroma augustum (brevicolpate aperture and reticulate- perforate exine sculpture). Waltheria subtype A (Fig. 2 a) : Pollen grains 4-zonocolporate, oblate - spheroidal ( x µm); colpi fusiform, its length ranges from µm long, tapering to the poles; ora lalongate. Specimens examined: Hermannia cuneifolia Jacq. Waltheria subtype B (Fig. 3 a) : Pollen grains 4 5 zonocolporate, prolate-spheroidal ( x µm); colpi oblong, its length ranges from µm long, rounded at the poles; ora subcircular with pluging out margin. Specimens examined: Waltheria indica L.

10 112 R. HAMDY AND E. SHAMSO a b c d Fig. 2. Equatorial view of pollen grains in SEM. a: Hermannia cuneifolia (lalongate ora). b: Guazuma ulmifolia (reticulate exine sculpture). c & d: Pterygota alata (colpus fusiform and reticulate- perforate exine sculpture). a b Fig. 3. Pollen grains in LM. a: Waltheria indica (4- zonocolporate apertures and ora with pluging out margin). b: Glososstemon bruguieri (colpus oblong with rounded poles and coarse reticulate exine sculpture). c: Firmiana simplex (colpus fusiform with tapering poles). c

11 POLLEN MORPHOLOGY OF STERCULIACEAE IN EGYPT 113 Brachychiton type Pollen grains 3-zonocolporate, (rarely 4 in Brachychiton discolor), vary from oblate spheroidal, prolate spheroidal, subprolate to prolate; mean polar axis ranges from µm; mean equatorial diameter ranges from µm; colpi fusiform or oblong (in Glososstemon bruguieri Desf.); ora lalongate or circular, sometimes faint; exine sculpture reticulate, reticulation fine to coarse. Three subtypes are distinguished as follows: Brachychiton subtype A (Fig. 2 b) : Pollen grains x µm; colpi fusiform with tapering poles, µm long; exine sculpture fine reticulate to reticulate. Specimens examined: Hermannia modesta (Ehrenb.) Mast., Guazuma ulmifolia Lam. and Sterculia balanghas L. Brachychiton subtype B (Fig. 3 b & c) : Pollen grains x µm; colpi fusiform with tapering poles or oblong with rounded poles, µm long; exine sculpture coarse reticulate. Specimens examined: Glososstemon bruguieri Desf. Brachychiton discolor C. Moore ex Muell., Sterculia foetida L. and Firmiana simplex (L.) W. Wight. Brachychiton subtype C (Fig. 2 c & d) : Pollen grains x µm; colpi fusiform with tapering poles, µm long; exine sculpture fine reticulate to reticulate, lumina of reticulum psilate or with minute perforation (in Pterygota alata Roxb.). Specimens examined: Brachychiton acerifolius (Cunn. ex G. Don) Macarthur, B. australis (Schott & Endl.) A. Terrac., B. populneus (Schott. & Endl.) R. Br., B. rupestris (T. Mitch. ex Lindl.) K. Schum. and Pterygota alata Roxb. Discussion Palynologically, Sterculiaceae is an europalynous family, characterized by the highly diversity of palynological features. Generally, pollen grains are in monads, radially symmetrical, isopolar, show reliable variations in size, shape, exine sculpture and aperture type. These variations are of taxonomic significances at various ranks, especially at generic level (Erdtman 1952, Sharma 1957 & Lakshmi 2003). Among the two main pollen groups; four major types with seven subtypes are recognized. The distribution of pollen types among the studied taxa revealed that: Dombeya type distinguished subfamily Dombeyoideae, in having large sized, echinate pollen grains with 3-zonoporate; meanwhile the other three pollen types (Abroma, Waltheria and Brachychiton types) are characteristic to the other two subfamilies Byttnerioideae and Sterculioideae; both have medium to small, reticulate pollen grains with trizonobrevicolpate or 3 to 4 5 zonocolporate. Byttnerioideae is an europalynous, comprises three tribes of which tribes Byttnerieae and Theobromeae characterized by the presence of only one pollen type. The Abroma type is characteristic to the taxa of tribe Byttnerieae (genus Abroma) in having a 3-zonobrevicolpate pollen aperture. While the Brachychiton

12 114 R. HAMDY AND E. SHAMSO type which characterized the third subfamily Sterculioideae, is also present among the genera of tribe Theobromeae of subfamily Byttnerioideae, with its three subtypes (A, B & C) regarding the variation in pollen size and exine sculpture (see key). The combination of two pollen types is only observed in tribe Hermannieae (subfamily Byttnerioideae) which is represented in Egypt by two genera (Waltheria & Hermannia) of which Hermannia cuneifolia and Waltheria indica have the Waltheria type which characterized by 4-5 zonocolporate pollen grains, while the third species Hermannia modesta show a close relation with species of tribe Theobromeae and those of subfamily Sterculioideae by having the pollen grains of Brachychiton type. The analysis of the morphological characters of pollen grains of the studied taxa is firstly revealed that the previously mentioned characters can be of great value at the generic level while its application to the specific level is rather limited. Secondly, the present study tend to support the treatment of Sterculiaceae as a distinct family rather than its merging to family Malvaceae with other families as Tiliaceae and Bombacaceae as regarded by Judd & Manchster (1997), Bayer et al. (1999) and Bayer & Kubitzki (2003) based on molecular data. This is in agreement with Lakshmi (2003), El Husseini (2006) and Perveen & Qaiser (2007), who treated Sterculiaceae, Tiliaceae and Bombacaceae as a polyphyletic group on the basis of gross morphological characters and pollen morphology. Thirdly, the pollen morphology showed that the evolutionary line within Sterculiaceae s. str. confirmed the views of Sharma (1967) and Lakshmi (2003). It revealed a more or less plesiomorphic characters among the studied species of tribes Byttnerieae, Theobromeae (subfamily Byttnerioideae) and Sterculieae (subfamily Sterculioideae) by having pollen grains with 3- zonocolporate and reticulate sculpture; while species of subfamily Dombeyoideae exhibited apomorphous characters with 3- zonoporate and echinate sculpture. Meanwhile tribe Hermannieae (subfamily Byttnerioideae) stands as intermediate with 3-, 4- or 4-5 zonocolporate and reticulate sculpture. Key for the 4 major types and 7 pollen subtypes of Sterculiaceae on the basis of pollen morphology of the 20 Egyptian species examined under (LM) and (SEM). 1.a. Exine sculpture echinate, pollen grains with 3- zonoporate. (Dombeya type) b. Exine sculpture reticulate, pollen grains not 3- zonoporate a. Echinae ± pillar-shaped with indistinct base, inter-spinal area granulate....dombeya subtype A 2.b. Echinae spine-shaped with bulbous and perforated base, inter-spinal area foveolate.. Dombeya subtype B 3.a. Pollen grains with 3 - zonobrevicolpate abroma type 3.b. Pollen grains with 3 or 4 5 zonocolporate a. Pollen grains with 4 5 zonocolporate(waltheria type) b. Pollen grains with 3 - zonocolporate (Brachychiton type) a. Pollen grains with 4 zonocolporate, colpus fusiform with lalongate ora.... Waltheria subtype A 5.b. Pollen grains with 4 5 zonocolporate, colpus oblong with subcircular ora with pluging out margin waltheria subtype B

13 POLLEN MORPHOLOGY OF STERCULIACEAE IN EGYPT a. Pollen grains small, polar view less than 18.2µm......Brachychiton subtype A 6.b. Pollen grains medium sized, polar view ranged from µm a. Exine sculpture coarse reticulate....brachychiton subtype B 7.b. Exine sculpture fine reticulate to reticulate brachychiton subtype C Acknowledgements : Grateful thanks to Dr. H. Hosni and Dr. A. Hosny (Botany Department, Faculty of Science, Cairo University) for the critical revision of the manuscript. References APG II (Angiosperm Phylogeny Group) (2003) An update of the Angiosperm phylogeny group classification for the orders and families of flowering plants APG II. Bot. J. Linn. Soc., 141 (4), Bayer, C., Fay, M. F., De Bruijn, A.Y., Savolainen, V., Morton, C. M., Kubitzki, K., Alverson, W. S. and Chase, M.W. (1999) Support for an expanded family concept of Malvaceae: A combined analysis of plastid atpb and rbcl DNA sequences. Bot. J. Linn. Soc., 129 (4), Bayer, C. and Kubitzki, K. (2003) Malvaceae- In: The Families and Genera of Vascular Plants, Kubitzki, K. (Ed.), Malvales, Capparales and non-betalain Caryophyllales, Vol. 5, Springer Verlag Berlin Heidelberg, New York, Germany. Bentham, G. (1862) Sterculiaceae. In: Genera Plantarum Bentham, G. & Hooker, J. D. (Ed.), Vol. 1, Reeve, London. Boulos, L. (2000) Flora of Egypt (Geraniaceae-Boraginaceae), Vol. 2, Al Hadara publishing, Cairo, Egypt, Boulos, L. (2009) Flora of Egypt Checklist, Revised annotated edition: Al Hadara Publishing, Cairo, Egypt. Chaudhuri, S.K. and Mallik, N. (1965) 1. Pollen morphological studies of the order Malvales. Bull. Bot. Soc. Bangladesh, 19, Cheek, M.R. (2007) Sterculiaceae. In: Flowering Plant Families of the World. Heywood V.H. et al. (Ed.), Firefly Books, Buffalo, N.Y, USA. Cristobal, C. L. (1968) Estudio morfologico de les granas de polen de Byttneria. Pollen et Spores, 10, Cronquist, A. (1988) The evolution and classification of flowering plants, 2 nd ed. New York Botanical Garden, Bronx, N.Y. Dahlgren, G. (1989) The last Dahlgrenogram: system of classification of the Dicotyledons. In Plant taxonomy, phytogeography and related subjects : Tan, K., et al. (Ed.), Edinburgh University, Edinburgh. Edlin, H. L. (1935) A critical revision of certain taxonomic groups of the Malvales, Part: 1. New Phytologist, 34, 1 20.

14 116 R. HAMDY AND E. SHAMSO El-Husseini, N. (2006) Pollen morphology of Tiliaceae Juss. and Sterculiaceae Vent. and their relations to Malvaceae Juss. in Egypt. Int. J. Agri. Bio., 8 (6), Erdtman G. (1952) Pollen Morphology and Plant Taxonomy Angiosperms Almqvist and Wiksell, Stockholm. Hosni A. H. and Araffa, S. (1999) Malvaceae in the flora of Egypt, 2. Pollen morphology and its taxonomic significance. Taeckholmia, 19 (2), Huxley, A., Griffiths, M. and Levy, M. (1992) The New Royal Horticultural Society Dictionary of gardening Vol. 1-4, Marton ward Processing ltd. Scarborough, Yorkshire, UK. Ikuse, M. (1956) Pollen Grains of Japan 303 pp. Hirokawa Publishing cooperation, Tokyo. Judd, W.S. and Manchester S.R. (1997) Circumscription of Malvaceae (Malvales) as determined by a preliminary cladistic analysis of morphological, anatomical, palynological and chemical characters. Brittonia, 49, Lakshmi, G.K. (2003) Palynological Studies on Certain Malvales, Ph. D. Thesis, Mahatma Gandhi University (Online Thesis). Litchfield, W.H. (1966) The pollen morphology of Australian Sterculiaceae. Pollen et Spores, 8, Mabberley, D.J. (1997) The plant Book, A portable Dictionary of the Vascular Plants 2 nd ed., 683 Cambridge Univ. Press. Melchior, H. (1964) Sterculiaceae A. Engler s. Syllabus der Pflanzenfamilien. 12, ed. Vol. 2., Berlin, Nikolassee. Moore, P.D., Webb, J.A. and Collinson, M. et al. (1991) Pollen Analysis 216 pp. Blackwell, London. Perveen, A. and Qaiser, M. (2007) Pollen Flora of Pakistan-Malvaceae- Grewioideae- LII. Pak. J. of Bot., 39 (1), 1-7. Perveen, A. and Qaise, M. (2009) Pollen Flora of Pakistan-Malvaceae-Dombeyoideae- LXII. Pak. J. Bot., 41(2), Praglowski, J. and Punt, W. (1973) An elucidation of the microreticulate structure of the exine. Grana, 13, Praglowski, J. and Raj, B. (1979) On some pollen morphological concepts. Grana, 18, Punt, W., Hoen, P.P., Blackmore, S., Nilsson, S. and Le Thomas. A. (2007) Glossary of pollen and spore terminology. Rev. Palaeobot. Palynol., 143, Rao, C.V. (1950) Pollen grains of Sterculiaceae. J. Indian Bot. Soc., 29, Robyns, A., Nilsson, S. and R. Dechamps, R. (1977) Sur la position systematique du genra Maxwellia Baillon Bull. Jard Bot. Nat., Belgium, 47,

15 POLLEN MORPHOLOGY OF STERCULIACEAE IN EGYPT 117 Saad, S. I. (1960) The sporoderm stratification in Malvaceae. Pollen et spores, 2, Schumann, K.M. (1890) Sterculiaceae. - In: Die Natürlischen Pflanzenfamilien Engler A. & Prantl, K.A.E. (Ed.), Vol. 3(6), Leipzig, Cobenhagen. Selling, O. (1947) Studies in Hawaiian pollen statistics. Part 2: The pollens of Hawaiian phanerogams No. 38, University of Hawaii press, Honolulu, Bishop Museum special Publication, 430 pp. Shamso, E. and Hamdy, R. (2010) Melhania steudneri (Sterculiaceae) new record for Egypt, and a synopsis of the Sterculiaceae in Egypt. Nordic J. Bot., 28, Sharma, B. D. (1967) Studies of Indian pollen grains in relation to plant taxonomy- Sterculiaceae. Bot. Sur. India, 35 (4), Takhtajan, A. (1997) Diversity and Classification of Flowering Plants. Columbia University Press, New York. Wodehouse, R. P. (1935) Pollen Grains, their Structure, Identification and Significance in Science and Medicine, MC Graw-Hill Book cooperation, New York, London, 574 pp. (Received 15/7/2010; accepted 27/9/2010) دراسة مورفولوجیة لحبوب لقاح العاي لة Sterculiaceae فى مصر وأھمیتھا التصنیفیة ریم حمدى وإیمان شمسو قسم النبات- كلیة العلوم- جامعة القاھرة- الجیزة- مصر. تم فحص حبوب اللقاح مورفولوجیا لعدد عشرون نوعا تمثل إثنى عشر جنسا من الا نواع المزروعة والبریة لعاي لة بودرة العفریت (Sterculiaceae) فى مصر من خلال المجھر الضوي ى والماسح الالكترونى على أساس العلاقة التمییزبة لخواص حبوب اللقاح والتى تشمل صفات الفتحات وزركشة السطح والحجم وصفات أخرى. وقد أسفرت ھذه الدراسة عن وجود أربعة أنماط ري یسیة وسبعة تحت نمطیة ھم: نمط الدومبیا (Dombeya) والذى یتمیز بثلاثة ثقوب وسطح ذا طراز شوكى ویضم ھذا النمط دومبیا تحت نمط أ (سطح محبب بین الا شواك) ودومبیا تحت نمط ب (سطح مخرم بین الا شواك) نمط الا بروما (Abroma) والذى یتمیز بثلاثة شقوق قصیرة وسطح ذا طراز شبكى- مثقب ونمط الوالزیریا (Waltheria) الذى یحتوى على أربعة أو خمسة شقوق مركبة وسطح شبكى- مثقب والذى ینقسم تبعا إلى تحت نمطین ھم: والیزیریا تحت نمط أ (الشق مغزلى مع فتحة مستعرضة) و والیزیریا تحت نمط ب (الشق مستطیل مع فتحة داي ریة) ونمط البراكیكیتون (Brachychiton) والذى یحتوى على ثلاثة ثقوب مركبة والسطح ذا طراز شبكى. ویتضمن تحت نمط أ (الحبوب صغیرة الحجم ومحورھا أقل من ١٨.٢ میكرومللیمتر) وتحت نمط ب (الحبوب متوسطة الحجم ویتراوح محورھا من ٢٧.٣-٤٤.٨٥ میكرومللیمتر) وقد تم مناقشة نتاي ج ھذه الدراسة مع المعالجة التصنیفییة الحالیة للعاي لة.