Biologia, Bratislava, 62/2: 148—156, 2007 Section Botany DOI: 10.2478/s11756-007-0023-6
Trichome micromorphology in Teucrium (Lamiaceae) species growing in Croatia
Renata JurišicGrubeši´ c´*, Sanda Vladimir-Kneževic´,DarioKremer, Zdenka Kalođera &JadrankaVukovic´
Faculty of Pharmacy and Biochemistry, University of Zagreb, Ante Kovači´ca 1,HR–10000 Zagreb, Croatia
Abstract: Micromorphological investigation of the types, dimensions and distribution of characteristic trichomes in leaves and stems in Teucrium L. species (T. arduini L., T. chamaedrys L., T. flavum L., T. montanum L., T. polium L., and T. scordium L. subsp. scordioides Schreb.) distributed in Croatia was carried out as part of the taxonomical study of the genus Teucrium. Secretory types of hairs, peltate and capitate hairs were observed on the epidermis of stems and leaves of all investigated species. Non-secretory, acicular hairs were almost completely lacking on stems of T. scordium subsp. scordioides. Flagelliform hairs were not found in T. flavum and T. polium. Cladose hairs were present only in T. polium.Thelargest micromorphological variability was established between wild and cultivated samples of T. arduini and T. scordium subsp. scordioides, while cultivated and wild specimens of T. polium were almost identical. Differences were primarily observed in trichome dimensions and much less in micromorphological features. Key words: Teucrium L.; micromorphology; plant hairs
Introduction with Pycnobotrys, Scorodonia with Stachyobotrys,and Scordium with Spinularia.K¨astner (1989) later im- Teucrium species have been used for centuries in folk proved his own proposal by creating subsections that medicine as a cholagoga, as well as antispasmodic, di- include groups formerly considered at the section level uretic, antidiabetic, antiphlogistic, antirheumatic, anti- (for instance, subsect. Polium and Chamaedrys within septic, anthelmintic, carminative and flavoring agents sect. Chamaedrys). Other important research on the (Gharabeih et al. 1988, 1989). From a taxonomical per- taxonomy of the genus and species belonging to dif- spective, the genus Teucrium has been divided into sev- ferent sections were published by Puech (1978), Valdés eral sections, identifiable through calyx shape and in- Bermejo & Sanchez Crespo (1978), K¨astner (1979, florescence structure. The most important initial works 1981, 1985, 1986), Manzanares et al. (1983), Bini Maleci on this topic were by Schreber (1774), Bentham (1835) & Servettaz (1991) and Servettaz et al. (1992) in order and Boissier (1879, according to Bini Maleci & Servet- to obtain better insight into this complex genus. taz 1991). Schreber (1774) evaluated variation on the Plant hairs (trichomes) are of great interest to de- basis of leaf width and dentate leaf tips and described scriptive and experimental botanists and data on these five taxa at the variety level. In further studies, these and indumenta are routinely included in many types characters were found to show great variation and are of of studies. As simple morphological tools, trichomes virtually no taxonomical significance (Mártonfi 1995). are useful due to the ease with which they are ex- These studies were resumed by McClintock & Epling amined and their almost universal occurrence, partic- (1946) for the flora of the New World and by Tutin & ularly among the ferns and flowering plants. Beyond Wood (1972) in Flora Europaea. These authors usually their purely descriptive use, comparative data may be subdivided the genus Teucrium into ten sections: Teu- important for the study of evolution and relationships, cropsis Benth., Teucrium Benth., Chamaedrys (Mill.) and for the roles of hairs in various aspects of physio- Schreb., Polium (Mill.) Schreb., Isotriodon Boiss., Py- logical and ecological adaptation (Payne 1978). Many cnobotrys Benth., Scorodonia (Hill) Schreb., Stachy- authors, such as Behnke (1984), Güemes et al. (1992), obotrys Benth., Scordium (Mill.) Benth., and Spin- Servettaz et al. (1994), Bini Maleci et al. (1995) and ularia Boiss. Based on a comparative study of in- Mráz (1998) emphasize the great value of trichomes florescences and flowers, K¨astner (1978) made a re- in modern taxonomy. According to Mráz (1998), tri- markable modification by proposing only six sections chome micromorphology in the genus Teucrium has by uniting sect. Chamaedrys with Polium, Isotriodon been studied mainly in the sections Chamaedrys and
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