Polystichum minutissimum sp. nov. (Sect. Haplopolystichum, Dryopteridaceae): The Smallest Polystichum Found in a Karst Cave in China

微小耳蕨（新種，半開羽耳蕨組）：最小的耳蕨屬種類發現於中國貴州一喀斯特岩洞

張麗兵(Li-Bing Zhang) ； 何海(Hai He)

《Botanical Studies》 50卷3期 (2009/07) Pp. 353-358

摘要

本文描述了在中國貴州一喀斯特岩洞中發現的耳蕨屬半開羽耳蕨組(Polystichum sect. Haplopolystichum)一新種：微小耳蕨(P. minutissimum)，並提供線繪圖與彩色照片以資辨識。該新種是耳蕨屬中迄今發現的植株最小的種。微小耳蕨與另一發現於貴州南部石灰岩地區的荔波耳蕨(P. liboense)最接近。兩者形態上最重要的區別是，微小耳蕨的羽片邊緣不具泌水器，而荔波耳蕨的羽片邊緣脈端具有明顯的泌水器。此外，微小耳蕨的葉片(1.3-3.8×0.7-1.1 cm) 及羽片（中部羽片2.9-5.8×2.8-4.5 mm）遠小於荔波耳蕨的葉片及羽片。微小耳蕨是適應於岩洞洞口的潮濕而陰冷的特殊生境的種類，因而可能對環境變化特別敏感，其生境應予以保護。

關鍵字

洞穴植物 ； 中國 ； 鱗毛蕨科 ； 貴州 ； 微小耳蕨 ； 最小的耳蕨 ； 半開羽耳蕨組

並列摘要

Polystichum minutissimum (sect. Haplopolystichum, Dryopteridaceae) from a karst cave in southern Guizhou, China, is described as new. Polystichum minutissimum is the smallest species in the genus. It is morphologically most similar to P. liboense, a species also described from a limestone area in southern Guizhou, but differs from P. liboense in lacking hydathodes near the margin of the pinnae. Additionally, P. minutissimum has much smaller lamina (1.3-3.8 × 0.7-1.1 cm) and pinnae (middle ones 2.9-5.8 × 2.8-4.5 mm). In fact, it has the smallest lamina and pinnae in the genus. Polystichum minutissimum grows in cool, moist, and twilight conditions in a cave, where it can be extremely sensitive to environmental changes, thereby raising concern for its conservation.

並列關鍵字

Cave flora ； China ； Dryopteridaceae ； Guizhou ； Polystichum minutissimum ； Smallest polystichoid fern ； sect. Haplopolystichum