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| Allium heterophyllum D.F.Xie & X.J.He, in Xie, Cheng, Price, ... et He, 2022. |
Abstract
Allium heterophyllum D.F.Xie & X.J.He, sp. nov. (Amaryllidaceae), is a new species from Henan, China and is described based on morphological and molecular evidence. It is morphologically most similar to A. dumebuchum in the rhomboid scape in cross-section. However, distinctive differences were detected in perianth color, leaf shape and cross-section, flowers’ density as well as flowering season. Similarly, the karyotype of A. heterophyllum is 2n = 2x = 16 and in A. dumebuchum is 2n = 4x = 32. Phylogenetic analysis based on nuclear ribosomal Internal Transcribed Spacers (ITS) and three cpDNA regions strongly supports that A. heterophyllum is a member of Allium section Rhizirideum and sister to the other species of this section (e.g. A. senescens, A. spirale, and A. prostratum). Currently, only one population and approximately 120 individuals were discovered; the development of scenic spots in this region may affect its growth and threaten this population. Therefore, this new species is preliminarily considered as Near Threatened (NT) according to criteria of the IUCN Red List.
Keywords: Allium, chromosome number, morphology, new species, phylogenetic analysis
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| Photograph of the Holotype of Allium heterophyllum. |
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| Living images of Allium heterophyllum A habitat, growing on the open slope of rock B, C inflorescence, light purple with loose flowers D bulb with the horizontal rhizome. |
Allium heterophyllum D.F.Xie & X.J.He, sp. nov.
Diagnosis: Allium heterophyllum resembles A. dumebuchum due to its rhomboid scape in cross-section. However, it is clearly distinguished from A. dumebuchum in perianth (white to light purple vs. light purple), leaves (not tortuous and not flesh vs. slight tortuous and flesh), the cross-section of leaves (two types vs. one type), flowers’ density (loose inflorescence vs. many-flowered) (Fig. 2; Table 2), flowering season (late August to September vs. late September to October), and karyotype (2n = 16 vs. 2n = 32) (Fig. 4). Compared to other Rhizirideum species (e.g., A. scenescens, A. spirale and A. spurium), A. heterophyllum also shows distinctive morphological characters, such as rhomboid scape in cross-section, unique two types of leaves, loose flowers, white to light purple color of perianth and filaments, and flowering season.
Habitat and ecology: Currently, A. heterophyllum is only known from the type population in Longchiman Mountains in Songxian County, Henan, China. This species grows on the open slope of rock by the river with a small amount of soil attached, sometimes rooting in crevices, holes or steps of the rock face at an elevation from 1250 m to 1400 m.
Etymology: The new species epithet “heterophyllum” is based on the unique leaves’ characters, its leaves exposed two types of morphologies, canaliculated with one bulge in the back or flat with irregularly one or two-edged margin, and the differences in the leaves are most obvious in flowering and fruit periods. (Fig. 2).
Chinese name: Yi Ye Jiu (异叶韭).
Deng-Feng Xie, Rui-Yu Cheng, Megan Price, Jun-Pei Chen, Jia-Qing Lei, Yi-Yang Zhang and Xing-Jin He. 2022. Allium heterophyllum (Amaryllidaceae), A New Species from Henan, China. PhytoKeys 190: 53-67. DOI: 10.3897/phytokeys.190.77449
