Breutelia tundrae is newly described from southernmost Chile. It seems to be restricted to the Magellanic tundra, and thus its name. It is distinguished by the expanded, appressed leaf base, often with lax cells at the shoulders, widest well above the insertion, with only scant alar differentiation. The upper laminal cells are long-rectangular, very thick-walled, and porose. It seems closest to the northern Andean B. karsteniana, which is similar in aspect. However, B. tundrae differs from B. karsteniana in having leaves slightly more spreading when dry (or moist) and somewhat shorter. In addition, the laminal cells are shorter, broader, even thicker-walled and more porose. The projecting prorulae are slightly taller than those in B. karsteniana. The species are best differentiated by differences in their leaf bases. In B. karsteniana they are spreading from the insertion and widest immediately above the insertion in the area of the extensively differentiated alar cells; in B. tundrae the leaf base is appressed to the stem, almost always orange, and widest well above the insertion and there are only 1–3 differentiated alar cells. A key to the species of Breutelia in the Cape Horn Archipelago is provided.

中文翻译：

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Breutelia tundrae (Bartramiaceae)，一种来自合恩角群岛的新苔藓物种（智利南极洲省）

Breutelia tundrae 是从智利最南端新近描述的。它似乎仅限于麦哲伦苔原，因此得名。它的特点是扩大的、贴伏的叶基部，通常在肩部有松散的细胞，在插入点上方最宽，只有很少的翼分化。上部层状细胞呈长矩形，壁非常厚，并且是多孔的。它似乎最接近于北安第斯 B. karsteniana，后者在外观上相似。然而，B. tundrae 与 B. karsteniana 的不同之处在于，在干燥（或潮湿）时，叶子会稍微散开一些，而稍微短一些。此外，层状细胞更短、更宽、壁更厚、孔隙更多。突出的 prorulae 比 B. karsteniana 中的稍高。通过叶基的差异可以最好地区分这些物种。在 B。karsteniana 它们从插入处开始扩散，并且在广泛分化的鼻翼细胞区域的插入处上方最宽；在 B. tundrae 中，叶基紧贴在茎上，几乎总是橙色，并且在插入处上方最宽，并且只有 1-3 个分化的鼻翼细胞。提供了合恩角群岛 Breutelia 物种的钥匙。