Abstract

A neglected species in the Flora of Taiwan and the Philippines (the Batan islets), Portulaca psammotropha Hance, is described and illustrated. Herein, Portulaca quadrifida var. formosana and P. insularis are treated as synonym of P. psammotropha. This species is a typical littoral plant that is scattered on coral sands and coral reef in the archipelago around SE China. It can be characterized by leaves alternate; leaf blade quite fleshy, oblong to obovate-oblong, 3-10 mm long, apex obtuse; petals 5, yellowish, ca. 3-5 mm long. The stamen number and stigma lobes of this species vary among the populations observed.

中文摘要

本文描述一種臺灣與菲律賓(巴丹群島)植物誌疏漏的植物：沙生馬齒莧，探討其分類地位及分布情形，並將寶島馬齒莧 Portulaca quadrifida var. formosana 與島嶼馬齒莧P. insularis 處理為本種的異名。沙生馬齒莧是典型的海濱植物，已知散生於中國大陸東南側島弧之珊瑚沙灘與珊瑚礁石上。本種具有下列形態特徵：葉互生，厚肉質，長橢圓至倒卵狀長橢圓形，長3-10 公釐，先端鈍；花瓣5，黃色，3-5 公厘長。而雄蕊與柱頭裂片的數目則在族群間有所不同。

Keyword: Neglected species, Portulaca psammotropha, Portulacaceae, Taiwan, Philippine. 沙生馬齒莧、馬齒莧科、疏漏種、臺灣、菲律賓。