Abstract

Since insufficient materials of Thismia taiwanensis were collected in the past, the structural details of the annulus, stamens and other characters of this critically endangered species have not been examined. The aim of this study was to determine the characteristics of flowers and fruits, especially those of the perianth tube and stamens, using fresh material. Seed surfaces were photographed by using scanning electron microscopy. The results showed that the flowers of T. taiwanensis were found either without a pedicel or with an elongated pedicel that becomes carnose in the fruit stage. The latter was more common. The perianth is not covered with glands; there are six stamens, which are separate and opposite the perianth lobes, with dilated, ribbon-like connectives, pendulous from annulus. The seeds are ellipsoid to fusiform, with somewhat tapering poles, 0.2-0.4 × 0.1-0.15 mm, and with epidermal cells that are raised, with distinctly longitudinal anticlinal walls and sunken anticlinal boundaries, forming a superficial network pattern.

中文摘要

臺灣水玉杯為嚴重臨危物種，因族群數量非常少，花被和雄蕊形態、種子表面顯微形態等或其他資料仍未加以描述。本研究將利用新鮮植株詳細描述其花被和雄蕊形態，並利用掃瞄式電子顯微鏡觀察種子表面顯微形態。研究結果顯示，臺灣水玉杯花莖有二型，一為無花莖，另一型為花莖延長且肉質增厚，野外以此型居多。臺灣水玉杯花被無腺點，雄蕊6，離生，與花被裂片同數而對生，藥膈膨大長方形扁平狀，懸垂著生於花被筒咽喉部。種子呈橢圓形至紡綞形，二端有點尖，0.2-0.4 × 0.1-0.15 mm，表皮細胞具明顯凸起的縱向垂直細胞壁和垂直凹陷的區域，而構成種子表面網狀形態。

Keyword: micromorphology, pedicel, seed coat, Thismia taiwanensis. 顯微形態、花莖、種皮、臺灣水玉杯。