Allium heterophyllum D.F.Xie & X.J.He, 2022

Xie, Deng-Feng, Cheng, Rui-Yu, Price, Megan, Chen, Jun-Pei, Lei, Jia-Qing, Zhang, Yi-Yang & He, Xing-Jin, 2022, Allium heterophyllum (Amaryllidaceae), a new species from Henan, China, PhytoKeys 190, pp. 53-67 : 53

Allium heterophyllum D.F.Xie & X.J.He sp. nov.

Figs 1 , 2 , 3

Type.

China. Henan Province: Songxian County, Longchiman mountains , 111°59'24.31"E, 33°41'25.61"N, 1347 m alt., 04 September 2021, Anonymous, XDF20210904 (Holotype: SZ; Isotype: SZ) .

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.

Description.

Perennial herbs, bulbs solitary, paired or clustered, ovate-cylindric or conical, 5.0-15 mm in diameter, tunics membranous, white, attached to a horizontal or oblique rhizome, 5.0-20.0 mm in diameter, surface usually blackish gray. Leaves linear, 5.0-10.0, solid in cross-section, 1.0-30.0 (-45.0) cm long and 1.5-4.0 mm wide, usually shorter than scape, sometimes equal to the length of scape, exposed sheaths in 1/7; cross-section of leaves exposed two types of morphologies, canaliculated with one bulge in the back or flat with irregularly one or two-edged margin; the leaves’ shape differences are most obvious in flower and fruit periods but not obvious in young leaves. Scapes rhomboid, solid in cross-section, 25.0-45.0 cm long, and 15.0-25.0 mm in diameter. Spathe 1-valved, persistent and inconspicuous; inflorescence umbellate hemispheric, loose. Pedicels equal, 10.0-15.0 mm; perianth white to light purple, inner tepals 4.0-6.0 mm, longer than outer ones, elliptical, apex obtuse; outer tepals 3.0-4.0 mm, ovate-elliptical. Filaments equal and exserted, white to light purple in the upper part, 1.5 × as long as perianth segments and connate at the base of the perianth. Outer one subulate, inner filaments narrowly triangular; anthers elliptical, purple-grey. Ovary obovoid, trigonous, white to light purple, without concave nectaries. 3 carpel and ovules 2 per locule, style exserted, stigma punctiform. Capsule obovate; seeds black, rhomboidal, 1.5-2.0 mm wide and 2.5-3.0 mm long (Fig. 2 ; Table 2 ).

Etymology.

The new species epithet " Allium 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 ).

Phenology.

Through two field investigations, A. heterophyllum was flowering from late August to September and fruiting from late September to October.

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.

Chinese name.

Yi Ye Jiu (异叶韭).

Figures

Figure 1. 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.

Figure 2. Morphological characters of Allium heterophyllum A, D single flower with light purple or white color B, E outer (left) and inner (right) tepals C, F inner (top) and outer (bottom) tepals and stamen G stamen and trait at the base H ovary I cross-section of ovary showing the carpels J-L the cross-section of leaf showing the blade characters M cross-section of rhomboid scapes N seeds' characters.

Figure 3. Photograph of the Holotype of Allium heterophyllum.

Figure 4. The chromosome complement of Allium heterophyllum (2 n = 2 x = 16).