Phyton (Buenos Aires)
versão On-line ISSN 1851-5657
Pappophorum phillippianum and Trichloris crinita grow in areas where traditional forages cannot establish. They are not food resources for excellence, but have some nutritional value to domestic livestock. Leaves and stems collected in a natural halophytic field were treated using current techniques for describing their epidermic and anatomical characteristics. Blades of both species have papillose adaxial epidermis, and it is also the case for the abaxial epidermis in T. crinita. Silica bodies are double-axe shaped or cross shaped. Both species show foliar glandular and eglandular trichomes. Only T. crinita shows prickles. Anatomically, both species show groups of fibers in the adaxial and abaxial sides. This can interrupt the sheaths of the vascular bundles. The first-order vascular bundles have a mestome and a parenchymatic sheath, while the second order ones only show the parenchymatic sheath. The chlorenchyma is radiated. Trichloris crinita has a middle rib towards the abaxial side with colorless parenchyma. Pappophorum phillippianum does not have it. The stems, which are circular, have ribs that are more important in P. phillippianum. The stem epidermis has silica bodies of different shapes, and P. phillippianum shows bicellular trichomes. There are subepidermic groups of fibers, more important in T. crinita, which alternate with chlorenchyma. Both species have a band of sclerenchymatic parenchyma within an inner position. This is where a ring of vascular bundles, with an outer half parenchymatic sheath, is located. Two more rings of bundles are found in the inner parenchyma, which complete the stem structure. The amount of sclerenchyma in leaves and stems reduces the digestibility of these species. However, the possibility of using them as forage, where other species cannot vegetate, enhances their economic importance.
Palavras-chave : Chloridoideae; Poaceae; Halophyte; Forage species.