ISSN: 2395-9525 Núm. 42, pp. 121-136, México, 2016 DOI: 10.18387/polibotanica.42.6 COMPARATIVE MORPHOLOGY AND ANATOMY OF THE LEAF AND STEM OF SPECIES OF ZANTHOXYLUM (RUTACEAE) FROM CENTRAL ARGENTINA MORFOLOGÍA Y ANATOMÍA COMPARADA DE LA HOJA Y EL TALLO DE LAS ESPECIES DE ZANTHOXYLUM (RUTACEAE) DEL CENTRO DE ARGENTINA Antonia J. Oggero1; Marcelo D. Arana1, y Herminda E. Reinoso2 1Orientación Plantas Vasculares, 2Orientación Morfología Vegetal, Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico Químicas y Naturales, Universidad Nacional de Río Cuarto, X5804ZAB, Río Cuarto, Córdoba, Argentina. Correo electrónico: [email protected]; [email protected]; [email protected] ABSTRACT whereas Z. coco is usually a deciduous tree with terminal inflorescences. Both species Zanthoxylum is one of the major genera of also share the presence of secretory cavi- Rutaceae with at least 200 species in tro- ties, glandular trichomes and hypostomatic pical and temperate regions worldwide. In leaves. However each species presents par- Argentina is represented by 10 species, two ticularities of the leaves structure that could of them inhabiting in the central region, the be important and related to the environment native Zanthoxylum coco and the naturalised that the plants develop. Zanthoxylum armatum var. armatum. These species are found in xerophytic deciduous Key words: Zanthoxylum armatum, Zan- forests of Chaco biogeographic province. thoxylum coco, xeric habitats, flora. Besides the floristic and ethnobotanical importance of these species, their leaves RESUMEN and stems have been scarcely studied. The objective of this contribution was to present Zanthoxylum es uno de los principales a comparative morphological and anatomi- géneros de Rutaceae con al menos 200 cal study of the leaves and young stems of especies de las regiones tropicales y temp- the species of Zanthoxylum from central ladas de todo el mundo. En Argentina está Argentina. The analysis was done using her- representado por 10 especies, dos de ellas baria vouchers, freshly collected and fixed habitan en la región central, Zanthoxylum material. The species share morphological coco, nativo, y el naturalizado, Zanthoxy- features, as armed stems, leaves alternate, lum armatum var. armatum. Estas especies odd-pinnately, 3- to many foliolate. The se encuentran en los bosques caducifolios main differences are that Z. armatum is an xerofíticos de la provincia biogeográfica evergreen shrub with axillar inflorescences del Chaco. A pesar de la importancia flo- 121 ISSN: 2395-9525 Núm.42: 121-136 Julio 2016 rística y etnobotánica de estas especies, They are shrubs, trees, or sometimes herbs, sus hojas y tallos han sido escasamente sometimes scrambling or scandent, some- estudiados. El objetivo de esta contribu- times armed, with aromatic volatile oils ción es presentar un estudio morfológico y contained in glands visible at surface of, anatómico comparativo de las hojas y tallos at least leaves, young branchlets, inflores- jóvenes de las especies de Zanthoxylum del cences, flower parts, fruit, or cotyledons in centro de Argentina. El análisis se realizó seed. The genus Zanthoxylum L. is one of the utilizando ejemplares de herbario, material major genera of Rutaceae with at least 200 fijado y fresco. Las especies comparten species in tropical (mainly) and temperate rasgos morfológicos, como tallos armados, regions of the world (Figueiredo Melo & hojas alternas, imparipinnadas, 3- multifo- Zickel, 2004; Zhang & Hartley, 2008). It lioladas. Las principales diferencias son que includes shrubs sometimes scrambling, Z. armatum es un arbusto de hojas perennes trees, or woody climbers, evergreen or con inflorescencias axilares mientras que deciduous, usually armed. The leaves are Z. coco suele ser un árbol de hojas caducas alternate, odd-pinnately 3- to many foliolate con inflorescencias terminales. Ambas or sometimes digitately 3-foliolate. Zan- especies también comparten la presencia thoxylum is represented in Argentina by 10 de cavidades secretoras, tricomas glandu- species, two of them inhabiting in central lares y hojas hipostomáticas. Sin embargo, region of the country, Zanthoxylum coco cada especie presenta particularidades de Gillies ex Hook. f. & Arn. and Zanthoxylum la estructura de las hojas que pueden ser armatum DC var. armatum. These taxa are importantes y relacionadas al ambiente en the only species of Zanthoxylum found in el que las plantas se desarrollan. Pampean hills of central Argentina, which belong to the biogeographic province of Palabras clave: Zanthoxylum armatum, Chaco (Morrone, 2001; 2004). This province Zanthoxylum coco, ambientes xéricos, flora. is characterized by xerophytic deciduous fo- rests of Vachellia caven (Molina) Seigler & INTRODUCTION Ebinger, Aspidosperma quebracho-blanco Schltdl., Celtis ehrembergiana (Klotzsch) The family Rutaceae Juss. is placed in Liebm., Lithraea molleoides (Vell.) Engl. order Sapindales primarily because of the and Zanthoxylum coco as predominant pinnately compound leaves, absence of resin species of trees. Although these species are ducts in the bark, wood rays, leaf veins, the studied in floristic, taxonomic and ethno- presence of triterpenoid compounds and flo- botanic treatments, there are very scarce wers with a distinct nectar disk (Cronquist, morphological and anatomical studies of 1992; AGP III, 2003; Judd et al., 2008) and vegetative organs of these species. includes species of great economic impor- tance as ornamental plants, medicinal or Anatomy describes the internal structure culinary uses or perfume industry such as the of plants and is considered as a source of orange, lemon, lime, kumquat, mandarine correct identification of taxa. Anatomy and grapefruit. The Rutaceae are represented centres on the spatial arrangement of the in Argentina by seven genera and approxi- dermal, ground, and vascular tissue systems mately 18 species (Seo and Xifreda, 2008). (Nancy & Dengler, 2002). Similarly foliar 122 ISSN: 2395-9525 Oggero, A.J. et al.: Comparative morphology and anatomy of the leaf and stem of species of Zanthoxylum, Central Argentina epidermal microscopic features like shape southwestern part of Cordoba province, of epidermal cell, type of stomata, presence Argentina (fig. 1). or absence of pubescence and cell wall thickness are also considered as useful The comparative morphological description tools for correct taxa identification and their of the leaves and stem was carried out using phylogenetic relationship with other taxa fresh material and herbaria specimens and (Stace, 1965; Babalola & Victoria, 2009). it is based in Escalante (1961) for Zan- thoxylum coco and Arana & Oggero (2009) Although Zanthoxylum coco is one of the for Zanthoxylum armatum. The herbaria most common species of trees in forests consulted were CORD, LIL, LP, SI, RCVC in central Argentina Hills and it is used as and RIOC, and digital images of the types medicinal plant (Battista et al., 2007), their (provided by G and K) were also seen. The leaves and stems have not previously been selected samples of the specimens collected studied. The shrub Zanthoxylum armatum were deposited in the Herbarium of Depar- is an important medicinal plant extensively tamento de Ciencias Naturales, Facultad de used, in the countries which is native, for Ciencias Exactas, Físico-Químicas y Natu- curing Pneumonia, tick infestation and rales, Universidad Nacional de Río Cuarto gum diseases (Iqbal & Hamayun, 2005), (RCVC) and registered as follows: fruit is used for toothache, dyspepsia, and seeds are used as condiment and flavoring Zanthoxylum armatum: agent (Arshad & Ahmad, 2005; Abbasi et ARGENTINA. Córdoba. Depto. Calamu- al., 2010). Recently the leaves and fruits chita, Embalse Cerro Pelado, A. J. Oggero were investigated for various pharmacolo- & M .D. Arana s.n. (RCVC); Villa Amancay, gical activities and has showed good results 14-III- 2009, M. D. Arana & A. J. Oggero including cytotoxic, phytotoxic, antipyretic s.n (RCVC); Depto. Río Cuarto, Alpa Co- activities and rationalise its local uses (Suks- rral, 30- III-2000, C. A. Bianco, s.n. (RCVC athan et al., 2009; Barkatullah et al., 2011) 3625). and in Argentina was found as naturalized species (Arana & Oggero, 2009). Keeping Zanthoxylum coco: in view the significance of morphological ARGENTINA. Córdoba. Depto. Calamuchi- and anatomical studies for taxonomy and ta, Embalse Cerro Pelado, 14-III- 2009, A.J. ecology, a comparative morphological Oggero & M.D. Arana s.n (RCVC); Depto. and anatomical study of the leaves and Río Cuarto, Sierra de Los Cóndores, 10- X- young stems of the species of Zanthoxylum 1997, M. Ceballos, s.n. (RCVC 3948). from central Argentina is carried out. Morphological studies MATERIAL AND METHODS The analysis of the stem and leaf structure Plant material was done using freshly collected material or fixed material. The leaves located in The collections of the botanical material the nodes of the middle part of the newest and the field observations were carried out branchlets (there is one leaf per node in Sierra de Comechingones, located in the along the stem) were used to carry out the 123 ISSN: 2395-9525 Núm.42: 121-136 Julio 2016 Fig.1. Location of Sierra de Comechingones (central Argentina) where the study was carried out. 124 ISSN: 2395-9525 Oggero, A.J. et al.: Comparative morphology and anatomy of the leaf and stem of species of Zanthoxylum, Central Argentina anatomical study. The samples were taken The stomatal density, trichomes and (just from