Thursday, October 31, 2019

[Botany • 2019] Ottelia fengshanensis (Hydrocharitaceae) • A New Bisexual Species of Ottelia from southwestern China


Ottelia fengshanensis Z.Z.Li, S.Wu & Q.F.Wang

in Li, Wu, Zhou, et al. 2019.

Abstract
Ottelia fengshanensis, a new species (Hydrocharitaceae) from southwest China is here described and illustrated. Comparing its morphological features to putative close relatives O. guanyangensis, it has 3–4 flowers (vs. 2–5) each spathe, hexagonal-cylindric fruit, white styles (vs. yellow), green leaves (vs. dark green) and fruit tiny winged (vs. winged obviously). Molecular phylogenetic investigation of four DNA sequences (ITS, rbcL, trnK5’ intron and trnS-trnG) and the Poisson Tree Processes model for species delimitation (PTP) analysis, further resolves O. fengshanensis as a new species that is close to O. guanyangensis with distinct support.

Keywords: karst, bisexual flowers, molecular phylogeny

Figure 2. Ottelia fengshanensis Z.Z.Li, S.Wu & Q.F.Wang.
 A Habitat B flowering plant C bisexual flower with red-green sepals D individual and leaf: triplinerved with conspicuous cross veins E fruit: Hexagonal-cylindric with tiny wings F the character of pollens by SEM G spathe H seeds.

Figure 3. Illustration of Ottelia fengshanensis Z.Z.Li, S.Wu & Q.F.Wang.
Drawn by Shuai-Jie Li. 

Ottelia fengshanensis Z.Z.Li, S.Wu & Q.F.Wang, sp. nov.

Description: The new species is similar to Ottelia guanyangensis in having bisexual flowers, three stamens, but differs through having (3)-4 flowers in each spathe (vs. 2–5), white styles (vs. yellow), green leaves (vs. dark green) and by fruits which are tiny winged (vs. obviously winged).

Figure 4. Phylogenetic tree and PTP analysis of Ottelia fengshanensis sp. nov. and Blyxa japonica as an outgroup. Posterior probabilities (PP > 0.70) and bootstrap values (BS > 70) based on Bayesian Inference and maximum likelihood (ML) analysis are shown above the branches.


Distribution and habitat: Ottelia fengshanensis is known from a single population in Fengshan County, Guangxi Province, China. The species inhabits a karst river less than 1.5 m in depth. Due to the complex underground river system in the karst region, it is probable that the species occurs in nearby areas as well.
  
Etymology: The epithet is derived from the name of Fengshan County, which is the only known locality of occurrence.


 Zhi-Zhong Li, Shuang Wu, Chun-Yu Zhou, Yan Liu, Guang-Wan Hu, Samuli Lehtonen, Qing-Feng Wang and Jin-Ming Chen. 2019. Ottelia fengshanensis, A New Bisexual Species of Ottelia (Hydrocharitaceae) from southwestern China. PhytoKeys. 135: 1-10.  DOI: 10.3897/phytokeys.135.38531