Hiptage is one of the largest genera of Malpighiaceae with about 30 species of woody lianas and shrubs growing in forests of tropical South Asia. So far, a total of 29 species have been recognized in this genus. H. benghalensis is the most well-known species due to its attractive and fragrant flowers; it is often cultivated as a tropical ornamental plant in gardens. 

During floristic surveys in southern and south-western Yunnan from 2009 to 2017, some populations of Hiptage were discovered and some plants were cultivated in Xishuangbanna Tropical Botanical Garden (XTBG), Chinese Academy of Sciences (CAS). 

XTBG researchers carried out detailed examination on the morphological and anatomical characters of the living plants and specimens and compared the living plants with the possible closely similar species. They found that the populations represented two species distinct from the known 29 species so far. 

The researchers confirmed that the two species are new to science. They named the two new species as H. pauciflora and H. ferruginea respectively and got them published in PhytoKeys.  

Morphologically, H. pauciflora shares certain characteristics with H. benghalensis in having elliptic-oblong leaf blades and sub-orbicular petals. It also shares similarities with H. multiflora in having leaf marginal gland dots, sub-orbicular calyx glands and not decurrent to pedicel, obovate middle wing of samara.  

H. pauciflora differs from H. benghalensis by lacking basal glands at the leaf base, calyx glands ovate, and so on. It differs from H. benghalensis by its fewer flowers, longer pedicels, without basal glands at the leaf base and elliptic sepals (vs. ovate). 

Very few details about their natural distribution and population status are currently known. The two new species, H. pauciflora and H. ferruginea, are thus regarded as data deficient (DD) according to the IUCN Red List Categories (IUCN 2012). 

H. pauciflora (Image by XTBG)

H. ferruginea (Image by XTBG)