Resumo

MARTINS, Lúcia R. Rocha et al. A preliminary morphological and anatomical study of the stem and leaf of Acanthospermum australe (Loefl.) Kuntze (Asteraceae-Heliantheae). Rev. bras. farmacogn. [online]. 2006, vol.16, n.1, pp. 42-52. ISSN 0102-695X.  http://dx.doi.org/10.1590/S0102-695X2006000100009.

Preliminary morphological and anatomical descriptions of stem and leaf of Acanthospermum australe (Loefl.) Kuntze were made in fresh and fixed material. Cross and superficial sections, stained with safranin/astra blue and Toluidine blue were analyzed at the light microscopic and the images were acquired by means the program Image Pro-Plus, version 4.0 (Media Cybertecnics). The surface of the stem and leaf were observed through scanning electronic microscopy. The species presents in the stem and leaf surface multicellular nonglandular trichome, uniseriate with a pointed edge and multicellular glandular trichome like a disk with a unicellular peduncle, in which is attached a series of five cells. The leaf presents anomocytic stomata in both surfaces a little prominent in relation to the level of the epidermal cells. The stem presents an initial secondary growth with evident secretory ducts in the cortex and pith.

Palavras-chave : Acanthospermum australe; structural aspects; vegetative organs; diagnose.