[Objective] Plants in the Vallisneria genus have similar external morphologies, with linear or
strap-shaped leaves, making it difficult to identify species in fields. Stamen numbers of the male flowers
are one of the distinguishing characteristics of species in Vallisneria Linn. The male flowers of Vallisneria
species are small, measuring only 1.5 mm. However, identifying the number of stamens in male flowers
by manual dissection and observation methods can be challenging. [Methods] This study utilized a hydroponic
pre-culture method with male plants and male flower primordia of Vallisneria to obtain naturally
opened male flowers. Anatomical observations of the male flowers, fruits, and seeds of three Vallisneria
species were conducted using anatomical microscopes. [Results] Microscopic observations revealed that
there was one stamen in male flowers of V. natans. The fruits were cylindrical in shape with a smooth
surface, and the seeds were wingless with longitudinal stripes. In V. spinulosa, there were two stamens
in male flowers. The fruits were triangular in shape with spines along the edges, and the seeds had wings.
In V. denseserrulata, there were two stamens in male flowers. The fruits were cylindrical with three edges
and smooth surface, and the seeds were wingless. [Conclusion] V. denseserrulata, V. spinulosa, V.
longipedunculata, and V. anhuiensis were reported as new distribution records of Vallisneria Linn. in
Anhui Province, China, where V. longipedunculata and V. anhuiensis are new species found in Anhui
