Morphology and molecular phylogeny reveal two new species in Russula sect. Ingratae from China

Abstract

Two new species of Russula are described and illustrated in this paper. Russula clavulus is recognised by a pale yellow pileus centre, white margin with tuberculate striation, white to pale lamellae with small pale yellow spots, white to light yellow spore print, subglobose to broadly ellipsoid spores with short or long ridges and hymenial cystidia on lamellae sides that are mainly subclavate or fusiform. Russula multilamellula is morphologically characterised by the brownish orange to hazel pileus centre and satin white to yellowish-white margin with brownish tinge, lamellulae that are usually irregular in length and often anastomosing with lamellae, subglobose to broadly ellipsoid spores with short or long ridges and clavate hymenial cystidia. The combination of morphological features and multigene phylogenetic analyses of ITS-nrLSU-RPB2-mtSSU data indicated that these two new taxa belong to Russula subg. Heterophyllidia sect. Ingratae.

Two new Asian species of Russula sect. Ingratae with unique basidiospore features for subg. Heterophyllidiae

“…The combination of these characters makes section Ingratae one of the more easily distinguishable groups in subgenus Heterophyllidiae Romagn. and it forms a well-supported, monophyletic lineage in recently published ITS (Li et al 2021) and multi-gene (Buyck et al 2018;Chen et al 2021;Han et al 2022;Song et al 2018) phylogenetic analyses.…”

“…(Romagnesi 1967). In North America and Asia, these same European names are still mostly used to refer to endemic, undescribed close relatives or sister taxa, although this situation is now changing in Asia with the recent description by Chen et al (2021) of R. multilamellulata B.Chen & J.F.Liang (as "R. multilamellula") and R. clavula B.Chen & J.F.Liang (as "R. clavulus"). Both Asian species are close relatives of R. grata and allies, notwithstanding the fact that their odor was described as "indistinct"; all other species in the 'grata' lineage develop a unique, strong and sweet smell of bitter almonds, which allows to recognize this complex already when collecting in the field.…”

Notes on four species of Russula subgenus Heterophyllidiae (Russulaceae, Russulales) from southern China

“…Morphological characteristics used to define species of subg. Heterophyllidiae have been extensively discussed in previous studies ( Chou and Wang, 2005 ; Li et al, 2013 , 2015 , 2018 , 2019 , 2021 ; Chen et al, 2014 , 2019 , 2021a , b , c , d ; Zhao et al, 2015 ; Zhang et al, 2017 ; Li and Deng, 2018 ; Song et al, 2018a , b , 2020 ; Wang et al, 2019 ; Yuan et al, 2019 ; Han et al, 2022 ; Song, 2022 ). Ecological preference, also a useful feature to delimitate species, receives little attention.…”

“…In China, 38 species of subg. Heterophyllidiae have also been described/reported, which greatly enriched the species diversity of this subgenus ( Ying, 1983 ; Chou and Wang, 2005 ; Li et al, 2013 , 2015 , 2018 , 2019 , 2021 ; Chen et al, 2014 , 2019 , 2021a , b , c , d ; Zhao et al, 2015 ; Zhang et al, 2017 ; Li and Deng, 2018 ; Song et al, 2018a , b , 2020 ; Wang et al, 2019 ; Yuan et al, 2019 ; Han et al, 2022 ; Song, 2022 ). Even so, the diversity and taxonomy still remained incompletely understood in the country.…”

“…In previous studies, about 161 species within subg. Heterophyllidiae were revealed around the world ( Ying, 1983 ; Li et al, 2013 , 2015 , 2018 , 2019 , 2021 ; Chen et al, 2014 , 2019 , 2021a , b , c , d ; Zhao et al, 2015 ; Zhang et al, 2017 ; Li and Deng, 2018 ; Song et al, 2018a , b , 2020 ; Wang et al, 2019 ; Yuan et al, 2019 ; Ghosh et al, 2020 ; Wisitrassameewong et al, 2020 , 2022 ; Vera et al, 2021 ; Altaf et al, 2022 ; Han et al, 2022 ; Song, 2022 ). Moreover, the edibility and poisonousness of the subgenus have also been noted, e.g., edible species, R. maguanensis J. Wang, X. H. Wang, Buyck and T. Bau, R. substriata J. Wang, X. H. Wang, Buyck and T. Bau, R. vesca Fr., and R. viridirubrolimbata J.…”