Festuca is a genus of the Poaceae family with about 140 species in South America. Little information is available about Festuca species growing in the Eastern Sierras Pampeanas in Argentina, a region with a significant degree of endemism. The taxonomic delimitation of some species of this region is imprecise. One such taxon is Festuca lilloi, which has not only been recognized as a native species of the Peruvian Andes or endemic to the Western Sierras Pampeanas (northern Argentina), but also as a dominant floristic element in the Eastern Sierras Pampeanas (central Argentina). In spite of its ubiquity, there is very little information on variation in its morphology, anatomy and ecology across the Sierras Pampeanas and in adjacent areas. Recent fieldwork has resulted in the finding of a new species of Festuca that was erroneously assigned to Festuca lilloi. Morphological and anatomical differences between F. lilloi and the close species are evaluated, as are the species’ ecological preferences. The delimitation of the new species, named here as Festuca giraldoi, follows the morphological species concept. A detailed description of the morphology, leaf anatomy and epidermal micromorphology (leaf and lemma) is provided for the new species.

中文翻译：

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Festuca giraldoi (Loliinae, Poaeceae), 阿根廷新种, 修订了 Festuca lilloi 的分类概念和特性

Festuca 是禾本科的一个属，在南美洲约有 140 种。关于生长在阿根廷东部山脉潘佩纳斯的羊茅物种的信息很少，该地区具有很大程度的特有性。该地区某些物种的分类划分不准确。一个这样的分类群是 Festuca lilloi，它不仅被认为是秘鲁安第斯山脉的本地物种或西潘佩纳山脉（阿根廷北部）的特有种，而且还是东潘佩纳山脉（阿根廷中部）的主要植物区系元素。尽管它无处不在，但关于其在潘佩纳山脉和邻近地区的形态学、解剖学和生态学变化的信息很少。最近的实地工作发现了一种新的羊茅属，该物种被错误地分配给了羊茅。评估 F. lilloi 和近亲物种之间的形态和解剖学差异，以及物种的生态偏好。新物种的定界，这里命名为 Festuca giraldoi，遵循形态学物种概念。为新物种提供了形态学、叶解剖学和表皮微形态（叶和外稃）的详细描述。