Prof. Zhu Hua of Xishuangbanna Tropical Botanical Garden (XTBG) recently described a new genus Paralasianthus from South-East Asia. When consulting a large amount of speciemens, Prof. Zhu Hua found that a group of closely related Asian species have been included in several different genera. Some of them were treated as Lasianthus, some as Saprosma and others as Amaracarpus. However, they have different features with these genera. This group of species thus has a combination of characters that separates it from similar genera; therefore, a new genus, Paralasianthus H. Zhu, is proposed to accommodate this group of species.

     This genus differs from Saprosma in the lack of conspicuous colleters on the inside of the base of the stipules and bracts (except very minute ones), petioles without articulation, and leaves with looped venation. It differs from Amaracarpus by being glabrous plants, with axillary or subaxillary cymes, stipules subulate or triangular, free, entire bracteoles, not forming a compact structure with stipules and reduced leaves. It differs from Lasianthus in usually having a 2-locular ovary and drupes with 2 thin-walled pyrenes. Its unique combination of characters, i.e. glabrous plants with very small stipules, looped leaf venation, usually 2-locular ovary and 2-pyrenate drupes, clearly separates it from Lasianthus, Saprosma and Amaracarpus.

  Five species are recognized in the genus, four of which required new combinations, P. brevipes, P. dichotomus, P. lowianus and P. hainanensis, and one is described as a new species, P. zhengyianus.

   Zhu Hua published the new genus in Phytotaxa. URL: http://biotaxa.org/Phytotaxa/article/view/phytotaxa.202.4.5

                       Paralasianthus zhengyianus H. Zhu