Researchers from the Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences have identified a remarkable new tree species in Yunnan Province, distinguished by its extraordinarily long, cascading floral displays.

The discovery was made during field surveys in the Tongbiguan Provincial Nature Reserve in southwestern Yunnan. The trees, belonging to the tropical genus Chisocheton of the Meliaceae family, immediately stood out due to their immense inflorescences and large, softly hairy seed capsules.

After careful morphological comparisons with herbarium species and digitized records, the researchers confirmed that the tree represented a new species. They named it Chisocheton megathyrsus to refer to the extremely long inflorescences, which reach an exceptional length of up to 2.5 meters.

The new species was published in Annales Botanici Fennici.

Chisocheton megathyrsus is a tree growing up to 20 meters tall. Its most striking feature is the pendulous, many-branched inflorescence bearing clusters of small, fragrant, yellowish-white flowers. Beyond its spectacular blooms, the species has large elliptical leaflets with a velvety texture and sizable, fuzzy, olive-brown fruits that can reach 10 cm in diameter.

Chisocheton megathyrsusis morphologically similar to Chisocheton dysoxylifolius, known from Bangladesh to Thailand. However, it is distinct in multiple traits: a longer, hairier leaf stalk, leaflets with more secondary veins, longer inflorescence branches, hairless anthers, and its uniquely large, cup-shaped floral disc.

To date, Chisocheton megathyrsus is known only from Nabang Township in Yingjiang County, Yunnan, where it grows in humid tropical forests at altitudes of 200–400 meters within the protected Tongbiguan Nature Reserve. Its restricted known range in lowland tropical forest makes it vulnerable to threats like habitat fragmentation from deforestation and agricultural expansion.

Notably, for decades, herbarium samples of this tree had been misidentified as Chisocheton cumingianus subsp. balansae, previously the only recognized member of its genus in China.

“The formal recognition of Chisocheton megathyrsus underscores the immense yet still-undocumented plant diversity in Yunnan's frontier forests,” said TAN Yunhong of XTBG.

Chisocheton megathyrsus (Image by TAN Yunhong)

Chisocheton megathyrsus (Image by TAN Yunhong)

Chisocheton megathyrsus (Image by TAN Yunhong)

Chisocheton megathyrsus (Image by TAN Yunhong)

Available online: 24 November 2025