What are gymnosperms (裸子植物)? Gymnosperms represent a heterogeneous group of vascular plants. One characteristic that traditionally lumps them together is their production of ovules that are 'naked' (not enclosed in an ovary). Living gymnosperms are classified into four divisions, namely, Cycadophyta (蘇鐵門), Ginkgophyta (銀杏門), Coniferophyta (Pinophyta 松柏門), and Gnetophyta (賣麻藤門). Morphological and molecular characteristics, including the flagellate sperms and nuclear 18s rRNA sequences, suggest that Cycadophyta and Ginkgophyta are the more primitive among gymnosperms. Representatives of all four divisions of gymnosperms are found in Hong Kong. Gymnosperms >> vascular plants