Microglossum capitatum was firstly collected on August 10, 1939 in Jinghong City, Xishuangbanna, Yunnan Province (H. S. Yao 7422 and H. S. Yao 8051), and was then formally described in 1944 by Tai Fang-Lan (Tai 1944).
Zhuang and Wang (1997) regarded M. capitatum as a synonym of M. longisporum E.J. Durand, which was originally described from the USA. Based on morphological and molecular phylogenetic data, we reveal that M. capitatum is different from M. longisporum and should be treated as an independent species.

Microglossum capitatum is a very rare species and has an extremely narrow distribution range. So far, it has only been reported in the Jinghong City, Xishuangbanna, Southwest China. It took 80 years to collect the species again near the type locality since 1939. The ascomata are distributed on the edge of Xishuangbanna National Nature Reserve and occur on the slope adjacent to a rubber plantation. The habitat is highly susceptible to the influence of human agricultural activity. They are facing severe threats of habitat loss and degradation.
We suggest this species to be categorized as Critically Endangered (CR).

The species has an extremely narrow distribution range. So far, it has only been reported in the Jinghong City, Xishuangbanna, Southwest China.

There are only 6 known collections of this species, two of which were collected in 1939. The other four were collected at the same location on August 25, 2019. It is only seen in a small area of Jinghong and the population is very small. There is no enough information about the trend of the population.

Microglossum captatum grows in flocks on moss-rich soil slopes at the edges of rubber plantation in summer. It is near the edge of tropical evergreen broad-leaved forest.

The main threat is the destruction of the original habitat by the development of rubber tree plantation,tea plantion ,banana plantation and etc. which causes the continuous shrinking of the habitat.

No action directed etc.

Fortunately, we have generated DNA sequences from specimens of M. capitatum from Yunnan and M. longisporum from the USA. Further analysis of the threat factors to the Chinese species will be conducted focused on its geographical distribution.