山羊百科，林文智老師的植物、山岳、攝影紀錄

Part I

Part II

Part III

• Hansen, B. 1992. The genus Ptyssiglottis (Acanthaceae). A taxonomic monograph Opera Botanica 116: 5-58.

1. Niissalo, Matti and Le Min Choo 2021 Flora of Singapore precursors, 25: Taxonomic notes on new discoveries from Bukit Timah Nature Reserve, including two native genera newly recorded Gardens’ Bulletin Singapore 73(1):33-48