Roczniki Akademii Rolniczej w Poznaniu CCCLXXXVII

Botanika – Steciana , , - www.au.poznan.pl/steciana ISSN -

SCANNING ELECTRON MICROSCOPIC STUDIES OF LEAF SURFACE IN TAXA OF L. DRACAENACEAE

MAŁGORZATA KLIMKO, JUSTYNA WILAND-SZYMAŃSKA

M. Klimko, Department of Botany, Agricultural University of Poznań, Wojska Polskiego C, - Poznań, Poland, e-mail: [email protected] J. Wiland-Szymańska, Department of , Adam Mickiewicz University of Poznań, Umultowska , - Poznań, Poland, e-mail: [email protected]

(Received: March , . Accepted: April , )

ABSTRACT. Foliar micromorphology of taxa (species, varieties, and cultivars) of the genus Dracaena was investigated by scanning electron microscopy (SEM). The study has revealed several interesting foliar features that were not previously reported in this genus. Leaves are characterized by anomocytic sto- mata and have no trichomes. Leaves are amphistomatic in species, except for Dracaena ellenbeckiana, D. refl exa and D. refl exa ‘Song of Jamaica’, which have hypostomatic leaves, and other taxa with nearly hypostomatic leaves (a strongly reduced density of stomata on the adaxial surface). Diff erences are espe- cially prominent in the position and distribution of stomata, and the type of cuticle and wax. Among the studied dracaenas, only stomata of D. draco, D. cinnabari, D. schizantha, D. ombet and D. ellenbeckiana are surrounded by a cuticular fl ange, which is characteristic of xerophytes, similarly as a thick cuticle with a wax layer and a high density of stomata on both sides (except for D. ellenbeckiana).

KEY WORDS: Dracaena, micromorphology, leaf, SEM

INTRODUCTION Africa (BOS ). The preferred habitats are rainforests (shrubby dracaenas) or semi-deserts (dragon tree). Some The family Dracaenaceae was fi rst described in species are adapted to living in other habitats, such as by Salisbury (BOS ). Depending on the taxonomic the ecotone between a forest and the seashore, or beds classifi cation, it contains either two genera, i.e. Dracae- of periodical rivers (BOS ). na L. and Sansevieria Thunb. (DAHLGREN et AL. ), Due to their ornamental leaves, Dracaena species are or only one – Dracaena (BOS ). In the past one more among the most important ornamental foliage in genus was distinguished, i.e. Pleomele Salisb. (BROWN Europe, North America (BOS ), Asia and Africa. The ), which was included in the synonymy of Draca- most frequently grown species are D. fragrans (L.) Ker ena (BOS ). The fi rst described species of this genus Gawler, D. marginata Lam. Hort., D. deremensis Engl., was (L.) L., assigned by Linnaeus to the D. refl exa Lam. and D. sanderiana Sander. genus Asparagus L. due to the similarity of their fl ow- The medicinal application has resulted in the inter- ers (BOS , WALKER ). The taxonomy of species est in chemical compounds found in dracaenas. Such belonging to this family is still not completely clarifi ed. studies concern primarily species producing red , Depending on the author, the number of species it com- i.e. D. cochinchinensis (Lour.) S.C. Chen (ZHENG et AL. prises is defi ned as for the whole family (BOS ), ), D. cinnabari Balf. (HIMMELREICH et AL. , (DAHLGREN et AL. ) or species for Sansevie- MASAOUD et AL. a, b, c, VESELÁ et AL. ), D. ria (KOLLER and ROST ), and between and draco (MIMAKI et AL. , GONZÁLEZ et AL. , species for Dracaena (PALMER and PITMAN , BOS HERNÁNDEZ et AL. ), D. tamaranae Marrero, Al- , DAHLGREN et AL. , MARRERO et AL. , meida & Gonzáles-Martin (GONZÁLEZ et AL. ), but WALKER ). also many others, e.g. D. concinna Kunth (MIMAKI et The geographical range of the family Dracaenaceae AL. ) and D. loureiri Gagnepain (MASAOUD et AL. is contained in the tropical zone with the exception b). Dracaenas contain steroidal saponins (DAHL- of South America. In the subtropical climate only D. GREN et AL. ). Dracaena aubryana (E. Morren) and draco and D. tamaranae A. Marrero, R.S. Almeida & M. D. marginata were included in DNA studies and their Gonzales-Martin are found in the Mediterranean area data were used to revise the taxonomic classifi cation (MARRERO et AL. ), as well as D. aletriformis (Haw.) of the order (BOGLER and SIMPSON , Bos in the subtropical zone in the Cape Province, South RUDALL et AL. ). M. Klimko, J. Wiland-Szymańska

The main objectives of this study were: () to analyse Royal Botanic Gardens (RBG) Kew, the Botanical Gar- in detail the sculpture of the leaf epidermis of Dracaena den of the Adam Mickiewicz University (BG-AMU) in taxa; and () to identify the characters that are of diag- Poznań (Poland), the Museum of Berlin-Dahlem (B) in nostic value for the diff erentiation of species and their Berlin (Germany), and the herbarium (POZG) (Table ). cultivars in the vegetative stage. The leaves were fi xed with AFE (acetic acid – forma- lin-ethanol). Voucher specimens are deposited at the Department of Botany, the Agricultural University of MATERIAL AND METHODS Poznań. The adaxial and abaxial surfaces between the mid- The study is based on taxa of Dracaena ( spe- vein and the leaf margin were observed under a Philips cies, fi ve varieties and eight cultivars). Plant material FEN and Zeiss Evo Scanning Electron Micro- was obtained from the Botanical Garden (BG) in Berlin, scope.

TABLE . Voucher information of materials used for study

No Taxon Collection . Dracaena aletriformis (Haw.) Bos cul. BG (---), Germany . D. americana Donn. Sm. Martinez, /- (B), Mexico; Croat (KRAM), Panama . D. arborea (Willd.) Link cul. BG (---), Germany; RGB (-), Kew . D. aubryana C.J. Morren cul. BG (---; ---), Germany . D. aurea Mann Degener, Degener, /- (B), Hawaii . D. cambodiana Piere ex Gagnep. Haw, /- (B), Haiwan . D. camerooniana Baker cul. BG (---), Germany . D. cinnabari Balf. f. cul. BG (---), Germany; RGB (-), Kew . D. conferta Ridl. Kadiw, /- (B), North Borneo . D. deremensis Engl. cul. BG (---), Germany; BG-AMU, Poland . D. deremensis ‘Bausei’ cul. BG (---), Germany; BG-AMU, Poland . D. deremensis ‘Compacta’ cul. BG (---), Germany; BG-AMU, Poland . D. deremensis ‘Green Stripe ‘ cul. BG-AMU, Poland . D. deremensis ‘Warneckii’ cul. BG (---), Germany; BG-AMU, Poland . D. draco (L.) L. cul. BG (---), Germany; BG-AMU, Poland; Baranowski, (POZG), Teneryfa . D. ellenbeckiana Engl. Bos, /- (B), Kenya; cul. BG-AMU, Poland; RGB (-), Kew . D. elliptica Thunb. & Dalm Humbert, /- (B), Madagascar . D. fernaldii St. John Degener, /- (B), Hawaii . D. forbesii Degener Hatheway, Morton & Yasuda, /- (B), Hawaii . D. fragrans (L.) Ker Gawler Wiland, Mboya, (POZG), Tanzania, cul. BG-AMU, Poland . D. fragrans ‘Lindenii’ cul. BG-AMU, Poland . D. fragrans ‘Massangeana’ cul. BG-AMU, Poland . D. hawaiiensis Deg. & Deg. Degener, Degener, /- (B), Hawaii . D. mannii Baker Bos, /- (B), Tanzania . D. marginata Lam. cul. BG-AMU, Poland . D. multifl ora Werbg. De Mesa, Viliamii, /- (B), Philippines . D. ombet Kotschy & Peyr. Fris et al., (RGB), Ethiopia . D. pendula Peyr. Chaon, /- (B), Malaya . D. refl exa Lam. Viguier, Humbert, /- (B), Madagascar; Wiland, Mboya (POZG), Tanzania . D. refl exa var. angustifolia Bak. Humbert, /- (B), Madagascar . D. refl exa var. lanceolata Pers. Humbert, /- (B), Madagascar . D. refl exa var. linearifolia Bak. Humbert, /- (B), Madagascar . D. refl exa ‘Song of India’ cul. BG-AMU, Poland . D. refl exa ‘Song of Jamaica’ cul. BG-AMU, Poland . D. schizantha Baker cul. RBG (-), Kew . D. steudneri Engl. Wiland, Mboya, (POZG), Tanzania; cul. RGB (-), Kew . D. surculosa Lindl. var. maculata cul. BG-AMU, Poland . D. surculosa Lindl. var. surculosa cul. BG (---), Germany; BG-AMU, Poland Scanning electron microscopic studies of leaf surface in taxa of genus Dracaena L. (Dracaenaceae)

The investigated microscopic qualitative features sidered as good diagnostic features for the identifi cation included the shape of epidermal cells, wall cuticular of species on the basis of foliar anatomy (KLIMKO and and wax patterns, the location and distribution of sto- WILAND, unpubl. data). mata, as well as the shape of cuticular thickenings of stomata. CUTICULAR AND WAX ORNAMENTATION

RESULTS AND DISCUSSION Details of the outer cuticle structure, such as thick- ness and ornamentation, vary in some species and also Despite intensive phytochemical research on dracae- depending on the side of the leaf surfaces. The highest nas, no information is available on its foliar micromor- variability in the cuticle between the adaxial and abax- phology (this information was orally confi rmed in ial surfaces was observed in six species: e.g. D. arborea by J.J. Bos), although the epidermal morphology is well (Willd.) Link (Figs. A, A), D. aubryana (Figs B, B), documented in the botanical literature for several other D. deremensis (Figs C, C), D. fragrans ‘Lindenii’ (Figs groups of angiosperms (STACE , BARTHLOTT and D, D), and D. surculosa (Fig. ). However, diff erences EHLER , JEFFREE , PETRONCINI et AL. , in leaf sculpture were not detected in D. draco (Figs SONIBARE et AL. , KLIMKO and TRUCHAN , F, F, ), D. cinnabari (Fig. ), D. schizantha (Fig. ), ALIERO et AL. , etc.). D. ombet (Fig. ), D. camerooniana, D. deremensis ‘War- The characters of structures are grouped into three neckii’, D. marginata and D. refl exa var. lanceolata. categories: () primary sculpture (shape of cells); () sec- Details of the structure of the outer cuticle, par- ondary sculpture, superimposed on primary sculpture ticularly its sculpture, attest to variation between spe- (relief of outer cell walls, caused mainly by cuticular or- cies. The cuticle can be either undulate on the abaxial namentation); and () tertiary sculpture, of epicuticular and adaxial epidermis (Figs E, E) or only adaxially secretions, mainly wax (BARTHLOTT , ). (Fig. D), due to long protuberances; either verrucose So far, in Floras of China, Zimbabwe, and North abaxially, with large (Figs A, B) or small verrucae America, keys to the identifi cation of species and mon- (Figs D, C); or smooth (Figs F, F, B, F); or mixed, ographs, only morphological leaf characteristics were i.e. composed of several types of structures, more or less taken into account, e.g. size, shape and colour (BOS homogenous. , JOHN , BOS and CULLEN , VENTER , On both surfaces in D. americana Donn. Sm., D. cin- YEE , MBUGUA and BEENTJE , WATSON and nabari, D. deremensis ‘Warneckii’ and D. cambodiana, DALLWITZ , etc.). rounded cuticular outgrowths are quite regular, mark- Among the studied taxa, have completely green edly elevated above the surface of the leaf blade, but in leaf blades ( species and only one cultivar, D. dere- D. aubryana only on the abaxial surface (Fig. B). mensis ‘Compacta’). Yellow or white stripe variegation is The leaf epidermal characters, such as cuticular or- observed in seven cultivars of D. deremensis, D. fragrans namentation, are constant in some species and variable and D. refl exa. In contrast, D. marginata has only red in others, and thus of great signifi cance in understand- margins, while in D. draco leaf margins are yellow or ing the relationships between and within species. The red. Spotted variegation is also found in Dracaena sur- leaf cuticle is one of the most characteristic features of culosa Lindl. var. maculata and var. surculosa. D. surcu- epidermal phenotype (MARTIN and JUNIPER ). losa is the only species in which varieties are recognized Tertiary sculpture concerns wax, which shows re- (BOS ). markable variation in the studied dracaenas. Detailed Our observations showed that leaf surface in most SEM observations of both surfaces showed that the wax taxa is smooth and shiny, except for D. surculosa layer is usually granulate (in taxa), e.g. in D. arbo- (smooth and slightly rough), and D. draco, D. cinnabari, rea (Figs A, A), D. fragrans ‘Massangeana’ (Figs E, D. ombet Kotschy & Peyr. and D. schizantha (rough and E) and ‘Lindenii’ (Figs D, D); but it forms fl akes in dull). The leaf blade can be straight or slightly undulate D. draco (Figs F, F, ), D. ellenbeckiana Engl. (Fig. D), (D. fragrans, D. camerooniana Baker). D. cinnabari (Fig. ) and D. schizantha (Fig. ), D. ombet The foliar micromorphology of Dracaena taxa is pre- (Fig. ), while rodlets in D. deremensis (Fig. C), both sented in Figs -. fl akes and granules in D. aubryana (Figs B, B), both rodlets and granules in D. surculosa var. maculata (Fig. A), or both crust and granules. EPIDERMAL CELLS In detail, the micromorphology of these crystalloids shows an extraordinary diversity of high systematic In all taxa investigated, the leaf epidermis consists of signifi cance. a single cell layer and has no trichomes. Epidermal cells on the adaxial and abaxial leaf surface vary consider- ably in size and shape. They are regularly or irregularly STOMATAL APPARATUS elongated, with straight and either straight or slightly undulate walls. The types and features of stomata are often consid- The characteristics of the leaf epidermis in Dracaena ered helpful in defi ning taxa. Stomata in all species of sp. are of particular taxonomic as well as phylogenetic the genus Dracaena are always anomocytic (the ranun- interest, because they diff er conspicuously between spe- culaceous type), without any subsidiary cells. In the cies. The size and shape of epidermal cells may be con- opinion of numerous authors, the stomatal complexes M. Klimko, J. Wiland-Szymańska

FIG. . SEM. Adaxial epidermis of Dracaena leaves with stomata, cuticle and wax: D. arborea (A), D. aubryana (B), D. deremensis (C), D. fragrans ‘Lindenii’ (D), D. fragrans ‘Massangeana’ (E), D. draco (F) (note young leaf) Scanning electron microscopic studies of leaf surface in taxa of genus Dracaena L. (Dracaenaceae)

FIG. . SEM. Abaxial epidermis of Dracaena leaves with stomata, cuticle and wax: D. arborea (A), D. aubryana (B), note the concentration of cuticle, D. deremensis (C), D. fragrans ‘Lindenii’ (D), D. fragrans ‘Massangeana’ (E), D. draco (F) (note young leaf) M. Klimko, J. Wiland-Szymańska

FIG. . SEM. Adaxial and abaxial epidermis of Dracaena surculosa leaves with stomata, cuticle and wax: var. maculata (A, B); var. surculosa (C, D). A, C the adaxial surface without subsidiaries are practically confi ned to the Li- D. draco (Figs F, F), D. aurea (Figs A, A), D. margi- liales and their more specialized derivatives. This type is nata (Figs B, F), and deeply sunken on both surfaces independently derived from the primitive type, contain- in D. cinnabari (Fig. ), D. schizantha (Fig. ), D. ombet ing numerous parastomatal cells and is most advanced (Fig. ) and less deeply (Fig. D) in D. ellenbeckiana and evolutionarily (STEBBINS and KUSH , ESAU ). D. draco (Fig. ) (which was confi rmed on the basis of Most of the species have amphistomatic leaves with transverse leaf sections). a nearly homogeneous distribution of stomata on either Only stomata in D. draco, D. cinnabari, D. ombet, side. Hypostomatic leaves are found in D. ellenbeckiana, D. schizantha on both sides and in D. ellenbeckiana on D. refl exa and D. refl exa ‘Song of Jamaica’, while taxa the abaxial leaf surface are surrounded by a thick cu- have hypostomatic leaves with a strongly reduced den- ticular fl ange, square or rectangular in outline, which sity of stomata on the adaxial leaf surface. Their density is characteristic of xerophytes (Figs D, , , , ). Cu- on those leaves is as high as - stomata·mm-. Stomata ticular thickenings only along stomata were found on are located in single rows, or in bands composed of two the adaxial side in D. arborea (Fig. A), D. deremensis or several rows lying next to one another over the en- (Fig. C), and on the abaxial side e.g. in D. deremensis tire area (D. cinnabari, D. ombet and D. schizantha). The ‘Bausei’ (Fig. A), D. marginata (Fig. B), D. multifl ora stomata of amphistomatic leaves are more abundant on (Fig. C, E), D. mannii Baker, D. refl exa, and D. dere- the abaxial than adaxial surface. This is typical of most mensis ‘Compacta’. angiosperms (FAHN ). The presence of the cuticular fl anges around stomata Leaves of the studied taxa show remarkable variation in only four species studied is of special importance. in the distribution of stomata in the surface view under Most of the studied dracaenas have leaves that are rath- SEM. In taxa, stomata are located  at the level of the er thin and usually not fl eshy. A number of xerophytic other epidermal cells on both surfaces, eg. in D. arbo- species have leaves that are rather rigid and coriaceous rea (Figs A, A), D. fragrans ‘Lindenii’ (Figs D, D), (leathery). Species of the dragon-tree group, e.g. D. ta- Scanning electron microscopic studies of leaf surface in taxa of genus Dracaena L. (Dracaenaceae)

FIG. . SEM. Abaxial epidermis of Dracaena leaves with stomata, cuticle and wax: D. deremensis ‘Bausei’ (A), note cuticular thickening along stoma, D. marginata (B), note cuticular thickening along stoma, D. multifl ora (C), note cuticular thickening along stoma, D. ellenbeckiana (D), note the concentration of cuticle maranae, D. ombet, D. schizantha Baker, D. serrulata ment of the Island where it grows (PETRONCINI Baker, and D. draco, are regarded as very slightly or et AL. ). It results from conducted investigations slightly succulent, while D. cinnabari as very succulent that the variation in micromorphological leaf charac- (MARRERO et AL. ). teristics e.g. in D. draco is connected primarily with the and D. schizantha exhibit the age of plants. Young leaves have stomata located at the largest number of xeromorphic features in foliar micro- same level as the other epidermal cells without the cu- morphology, such as a thick layer of cuticle and wax; ticular ring, a thin layer of the cuticule and wax (Figs very strongly cutinised ledges of stomata, especially the D, D). Signifi cant interspecifi c diff erences are found outer ones, which cause leaf roughness; stomata very in the distribution of stomata. In D. cinnabari stomata deeply sunken, surrounded by a thick cuticular ring; and are arranged over the entire surface of leaf upper and high stomatal density (Figs , ). Both species diff er in underside, in D. draco in regular rows (Fig. ) and in the shape of the cuticular stomatal ring, the thickness D. ombet irregular. In this study, we used plants grow- of the epicuticular layer (thicker than in D. schizantha) ing under similar cultivation conditions, to minimize and the pattern of cuticules. the modifying eff ect of environmental conditions on the PETRONCINI et AL. () reported that the leaves of variation in epidermal leaf traits. D. cinnabari are most closely related to D. draco. Their Leaves of species of the dragon-tree group, i.e. D. dra- study of the anatomy of the two species has revealed co, D. cinnabarii, D. ombet and D. schizantha, diff er re- a considerable amounts of wax on the leaf lamina. The markably not only in their micromorphology (Figs -), high concentration of wax found in D. cinnabari may but also anatomy (KLIMKO and WILAND unpubl. data). possibly be connected with the unique climate (with Thus, species of the dragon-tree group require further de- mean annual precipitation of mm) and environ- tailed research, both concerning their micromorphology M. Klimko, J. Wiland-Szymańska

FIG. . SEM. Adaxial (A, B) and abaxial (C, D) epidermis of Dracaena draco leaves with stomata, cuticle and wax (note the concentration of cuticle)

FIG. . SEM. Adaxial (A, B) and abaxial (C, D) epidermis of Dracaena cinnabari leaves with stomata, cuticle and wax (note the concentration of cuticle) Scanning electron microscopic studies of leaf surface in taxa of genus Dracaena L. (Dracaenaceae)

FIG. . SEM. Adaxial (A, B) and abaxial (C, D) epidermis of Dracaena schizantha leaves with stomata, cuticle and wax (note the concentration of cuticle)

FIG. . SEM. Adaxial (A, B) and abaxial (C, D) epidermis of Dracaena ombet leaves with stomata, cuticle and wax (note the concentration of cuticle) M. Klimko, J. Wiland-Szymańska and anatomy, since RUDAL et AL. () defi ned the Dra- BOS J.J. (): Dracaenaceae. In: The families and gen- caenaceae as leaf succulents, while JANKALSKI () re- era of vascular plants. Flowering plants – Monocoty- garded the genus Dracaena as not genuinely succulent. ledons; Lilianae (except Orchidaceae). Vol. . Ed. K. This study of the foliar micromorphology of Dracae- Kubitzki. Springer, Berlin: -. na has revealed for the fi rst time a number of important BOS J.J., CULLEN J. (): Dracaena Linnaeus. In: The micromorphological characters, some of which exhibit European garden fl ora. A manual for the identifi ca- interesting interspecifi c variation, considered of signifi - tion of plants cultivated in Europe, both out-of-doors cance for their identifi cation. Micromorphological char- and under glass. Pteridophyta, Gymnospermae, An- acters, especially those of the abaxial epidermis, show giospermae – (Part I). Vol. . Cam- greater variation between taxa and thus are more useful bridge University Press, Cambridge: -. in the taxonomy of this genus. BROWN N.E. (): Notes on the genera , Dra- caena, Pleomele, Sansevieria and Taetsia. Sansevieria : -. CONCLUSIONS DAHLGREN R.M.T., CLIFFORD H.T., YEO P.F. (): The families of the Monocotyledons. Structure, evolution, Epicuticular waxes and cuticle on both leaf surfaces and taxonomy. Springer, Berlin. exhibit great micromorphological diversity. In the genus ESAU K. (): Plant anatomy. Wiley, New York. Dracaena leaves are amphistomatic, hypostomatic and FAHN A. (): Plant anatomy. Pergamon Press, Exeter: hypostomatic with a strongly reduced density of sto- -. mata on the adaxial surfaces. Stomata elliptic in outline GONZÁLEZ A.G., LEÓN F., HERNÁNDEZ J.C., PADRÓN J.I., are located in the level of the epidermis. Only stomata SÁNCHEZ-PINTO L., BERMEJO-BARRERA J. (): Fla- of D. draco, D. cinnabari, D. ombet, D. schizantha and vans of dragon’s blood from Dracaena draco and Dracae- D. ellenbeckiana are surrounded by a cuticular fl ange. na tamaranae. Biochem. Syst. Ecol. : -. The leaves are characterized by anomocytic stomata and HERNÁNDEZ J.C., LEÓN F., QUINTANA J., ESTÉVEZ F., have no trichomes. BERMEJO J. (): Icogen, a new cytotoxic steroidal saponin isolated from Dracaena draco. Bioorg. Medic. Acknowledgements Chem. : -. The study was supported by a grant from the Agri- HIMMELREICH U., MASAOUD M., ADAM G., RIPPERGER H. cultural University of Poznań and the Adam Mickiewicz (): Damalachawin, a trifl avonoid of a new struc- University of Poznań (Poland). We are especially grate- tural type from dragon’s blood of Dracaena cinnabari. ful to Dr. Beat Leuenberger from the Botanical Garden Phytochemistry : -. Berlin-Dahlem for his help and kindness. JANKALSKI S. (): Sansevieria versus Dracaena. San- sevieria : -. JEFFREE C.E. (): The cuticle, epicuticular waxes and REFERENCES trichomes of plants, with reference to their structure, functions and evolution. In: Insects and the plant ADOLT R., PAVLIS J. (): Age structure and growth surface. Eds B. Juniper, R. Southwood. Edward Ar- of Dracaena cinnabari populations on Socotra. Trees nold, London: -. : -. JOHN S.H. (): Monograph of Hawaiian species of ALIERO A.A., GRIERSON D.S., AFOLAYAN A.J. (): The Pleomele (). Hawaii. Plant Stud. Pac. Sci. , foliar micromorphology of Solanum pseudocapsicum. : -. Flora : -. KLIMKO M., TRUCHAN M. (): Morphological vari- BARTHLOTT W. (): Cuticular surfaces in plants. In: ability of the leaf epidermis in selected taxa of the Progress in Botany . Eds H.D. Behnke, K. Esser, genus Ficus L. (Moraceae) and its taxonomic implica- K. Kubitzki, M. Runge, H. Ziegler. Springer, Berlin: tions. Acta Soc. Bot. Pol. , : -. -. KOLLER A.L., ROST T.L. (): Leaf anatomy in Sanse- BARTHLOTT W. (): Scanning electron microscopy of vieria (Agavaceae). Amer. J. Bot. : -. the epidermal surface in plants. In: Scanning Elec- MARRERO A., ALMEIDA R.S., GONZALES-MARTIN M. tron Microscopy in taxonomy and functional mor- (): A new species of the wild dragon tree, phology. Ed. D. Claugher. Systematics Association Dracaena (Dracaenaceae) from and Special. Vol. . Clarendon Press, Oxford: -. its taxonomic and biogeographic implications. Bot. BARTHLOTT W., EHLER N. (): Raster Elektronen- J. Linn. Soc. : -. -mikroskopie der Epidermis – Oberfl äche von Sper- MARTIN J.T., JUNIPER B.E. (): The cuticle of plants. matophyten. Tropische und Subtropische Pfl aschen- Edward Arnold, London. welt. Vol. . Steiner Verlag, Wiesbaden. MASAOUD M., RIPPERGER H., HIMMELREICH U., ADAM BOGLER D.J., SIMPSON B.B. (): Phylogeny of Aga- G. ( a): Cinnabarone, a bifl avonoid from drag- vaceae based on ITS & DNA Sequence Variation. Am. on’s blood of Dracaena cinnabari. Phytochemistry J. Bot. , : -. : -. BOS J.J. (): Dracaena in West Africa. Agric. Univ. MASAOUD M., RIPPERGER H., PORZEL A., ADAM G. ( Wageningen Pap. : -. b): Flavonoids of dragon’s blood from Dracaena cin- BOS J.J. (): Dracaena – Dragon tree family. In: Flora nabari. Phytochemistry : -. of Zimbabwe. http://www.zimbabwefl ora.co. Scanning electron microscopic studies of leaf surface in taxa of genus Dracaena L. (Dracaenaceae)

MASAOUD M., SCHMIDT J., ADAM G. ( c): Sterols and STEBBINS G.L., KUSH G.S. (): Variation in the organi- triterpenoids from Dracaena cinnabari. Phytochemi- zation of the stomatal complex in the leaf epidermis stry : -. of monocotyledons and its bearing on their phylog- MBUGUA P., BEENTJE H. (): Dracaenaceae. In: Flora eny. Am. J. Bot. : -. of Tropical East Africa. T:\FTEA.WKG\inprepn\ VENTER S. . The genus Dracaena L. in South Africa, Dracaena.doc a revision. Aloe : -. MIES B., ZIMMER H. (): Die Vegetation der In- VERTHOEK S., HESS W.J. (): Agavaceae Dumortier. sel Sokotra im Indischen Ozean. Nat. Mus. : Flora of North America. Xerophytic plants. Flora . -. http://www.efl oras.org./fl orataxon.asp? MIMAKI Y., KURODA M., IDE A., KAMEYAMA A., YOKO- VESELÁ D., MAREK R., UBIK K., LUNEROVÁ K., SKLENÁR SUKA A., SASHIDA Y. (): Steroidal saponins from V., SUCHÝ V. (): Dracophane, a metacyclophane aerial parts of Dracaena draco and their cytostatic ac- derivative from the resin of Dracaena cinnabari Balf. tivity on HL- cells. Phytochemistry : -. Phytochemistry : -. MIMAKI Y., KURODA M., TAKAASHI Y., SASHIDA Y. (): WALKER C. (): A tale of dragons – a pachycaul spe- Steroidal saponins from the stems of Dracaena cies of Dracaena. Bull. Chem. Soc. Jpn. : -. concinna. Phytochemistry : -. WATSON L., DALLWITZ M.J. (): Dracaenaceae R.A. PALMER E., PITMAN N. (): Trees of Southern Africa. Salisbury. The families of fl owering plants. http:// P.P: I-X V + -. A. A. Balkema, Cape Town. delta–intkey.com/angio/www/dracaena.htm. PETRONCINI S., MARCHESELLI M.P., BRUSCHI P. (): XINGI CH., SING-CHI CH., TURLAND N.J. (): Dracae- Preliminary aspects of the anatomy and genetic vari- na Vandelli ex Linnaeus. Flora of China : -. ability of Dracaena cinnabari Balf. fi l: a threatened en- http://www.efl oras.org/fl orata demic species of Socotra Island, South . J. Agric. YEE J. (): Native Hawaiian plants. http://home ha- Environ. , -: -. waii.rr.com/yee/nativeplants.htmi. RUDALL P.J., CONRAN J.G., CHASE M.W. (): System- ZHENG Q.-A., ZHANG Y.-J., LI H.-Z., YANG CH.-R. (): atics of Ruscaceae/Convallariaceae: a combined mor- Steroidal saponins from fresh stem of Dracaena phological and molecular investigation. Bot. J. Linn. cochinchinensis. Steroids : -. Soc. : -. SONIBARE M.A., JAYEOLA A.A., EGUNYOMI A., MURATA J. (): A survey of epidermal morphology in Ficus For citation: Klimko M., Wiland-Szymańska J. (): Linn. (Moraceae) of Nigeria. Bot. Bull. Acad. Sin. : Scanning electron microscopic studies of leaf surface in -. taxa of genus Dracaena L. (Dracaenaceae). Rocz. AR Pozn. STACE C.A. (): Cuticular studies as an aid to plant , Bot.-Stec. : -. taxonomy. Bull. Br. Mus. (Nat. Hist.) Bot. : -.