Anatomical Findings of the Genus Galium L. (Rubiacaeae) in Egypt and Their Systematic Implications

Transverse stem sections of 11 species and 2 subspecies of the genus Galium L. from Egypt were studied by light microscopy. Epidermal cell shape, cortex, xylem, and pith were of good taxonomic value between the taxa. Four types of stem shape were discerned in the transverse sections. The shape of epidermal cells can be used to distinguish between subspecies of Galium setaceum Lam. The cortex varied in size from wide to very narrow. The pith was wide or narrow, and solid or hollow, and was useful for classifying species into groups. A key for the identification of the investigated taxa based on anatomical characters is provided.

Anatomical Findings of the Genus Galium L. (Rubiacaeae) in Egypt and Their Systematic Implications

Transverse stem sections of 11 species and 2 subspecies of the genus Galium L. from Egypt were studied by light microscopy. Epidermal cell shape, cortex, xylem, and pith were of good taxonomic value between the taxa. Four types of stem shape were discerned in the transverse sections. The shape of epidermal cells can be used to distinguish between subspecies of Galium setaceum Lam. The cortex varied in size from wide to very narrow. The pith was wide or narrow, and solid or hollow, and was useful for classifying species into groups. A key for the identification of the investigated taxa based on anatomical characters is provided.

___

  • Abdel Khalik K & Bakker FT (2007). Nasturtiopsis integrifolia (Boulos) Abdel Khalik & Bakker (Brassicaceae), a New Combination, and Cruciata articulata (L.) Ehrend. (Rubiaceae), a New Record for the Flora of Egypt. Turk J Bot 31: 571-574.
  • Abdel Khalik K, Abd El-Ghani MM & El Kordy A (2007). A Palynological study of Galium L. (Rubiaceae) in Egypt and its systematic implication. Feddes Repertorium 118: 311-326.
  • Abdel Khalik K, Abd El-Ghani MM & El Kordy A. (2008). Fruit and seed morphology in Galium L. (Rubiaceae) and importance for taxonomic identification. Acta Bot Croat 67: 1-20.
  • Boulos L (1995). Flora of Egypt, Checklist. Cairo: Al Hadara publishing.
  • Boulos L (2000). Flora of Egypt vol. 2: 229-242. Cairo: Al Hadara publishing
  • Delprete PG (1999a). Rondeletieae (Rubiaceae). Part 1. Fl. Neotrop. Monogr. 77: 1-226.
  • Goodman AM (2005). Mechanical Adaptations of Cleavers (Galium aparine). Ann Botany 95: 475-480.
  • Mabberley DJ (1987). The plant-book. P. 235. Cambridge: Cambridge University Press.
  • Metcalfe CRL & Chalk (1950). Anatomy of the dicotyledons, vol. 2. Oxford: Clarendon Press.
  • Tackholm V (1974). Students’ Flora of Egypt, ed. 2. Cairo: Cairo University Press.
  • Torres N, Saez L, Mus M & Rossello JA (2001). The taxonomy of Galium crespianum J.J. Rodr. (Rubiaceae), a Balearic Islands endemic revisited. Bot J Lincan Soc 136: 313-322.
  • Willis JC (1985). A dictionary of the flowering plants and ferns. 8th ed. (revised by H.K. Airy Shaw), P. 475. Cambridge: Cambridge University Press.