Huchimingia Z.Q. Song & Shi J. Li, 2022

Song, Zhu-Qiu, Li, Shi-Jin & Mattapha, Sawai, 2022, Huchimingia, a new genus segregated from Millettia (Leguminosae, Millettieae) based on morphological and molecular evidence, Phytotaxa 532 (1), pp. 37-56 : 46

Huchimingia Z.Q. Song & Shi J. Li , gen. nov.

≡ Millettia sect. Podocarpae Dunn, J. Linn. Soc., Bot. 41(280): 135. 1912.

Type: Huchimingia ichthyochtona (Drake) Z.Q. Song ≡ Millettia ichthyochtona Drake, J. Bot. (Morot) 5(12): 187. 1891.

Diagnosis. The new genus Huchimingia is most closely related to Antheroporum and Ohashia within the non-canavanine group of the core Millettieae ( Fig. 1 ). Huchimingia is distinguished from Antheroporum by having conspicuous buds covered with scales (vs. inconspicuous), single inflorescence in the leaf axil (vs. 3‒5 inflorescences), large (vs. small) flowers, distinct (vs. indistinct) hypanthium, ebracteolate calyx (vs. two bracteoles at the base of calyx), triangular (vs. subtruncate) calyx lobes, oblong (vs. elongated) wing petals, and flat (vs. inflated and vacuous) pods. Huchimingia is morphologically distinguished from Ohashia by its tree (vs. liana) habit, conspicuous buds covered with scales (vs. inconspicuous), very indistinct (vs. distinct and thick) brachyblasts, 2 (vs. 7‒10) flowers per brachyblast, ebracteolate flowers (vs. two bracteoles at the base of calyx), large (vs. small) flowers, distinct (vs. indistinct) hypanthium, oblong (vs. elongated) wing petals, stipitate (vs. estipitate) ovary, and stipitate and dehiscent (vs. estipitate and indehiscent) pods. Additionally, Huchimingia is also related to Hesperothamnus ( Fig. 1 ), but it differs in having conspicuous buds covered with scales (vs. inconspicuous), leaves without (vs. with) stipels, very indistinct (vs. distinct) brachyblasts, 2 (vs. 3‒5) flowers per brachyblast, distinct (vs. indistinct) hypanthium, stipitate (vs. estipitate) ovary and pod, and Asian (vs. American) distribution.

Genus description. Deciduous trees. Buds axillary or pseudo-terminal, large, subglobose, scaly. Stipules linear to ovate, caducous. Leaves alternate, imparipinnate; leaflets 3‒15, (sub)opposite; principal lateral veins pinnate, curved apically near margins; stipels absent. Inflorescence an axillary and solitary pseudoraceme or pseudopanicle, inserted at previous branchlets short, usually 4–10 cm long, with laxly flowers; brachyblast very indistinct, always with 2 flowers; bract subtending the indistinct brachyblast large, conspicuous, longer than the corresponding flower buds; floral bract filiform, inserted at the base of each pedicel; bracteole absent (or strongly reduced at the middle of pedicel). Flower large, 14‒25 mm long; hypanthium distinct, hollow inside; calyx hairy outside, with 5 lobes, two upper lobes connate in a shortly 2-dentate upper lip; petals white; standard petal suborbicular, reflexed at base, basal callosities absent; wing petals oblong; keel petals falcate; androecium pseudo-monadelphous with distinct basal fenestrae; disk absent; ovary stipitate, ovules 2‒6, tending to be at or beyond the center of the ovary. Pods dehiscent, leathery to woody, stipitate; both sutures with or without two wings. Seeds 1‒4, suborbicular and compressed, with a well-developed aril. Seedling epigeal, phanerocotylar; first two eophylls opposite, 7–9-foliolate.

Etymology. This new genus is named in honor of Professor Chi-Ming Hu (1935‒) from South China Botanical Garden, Chinese Academy of Sciences, who made important contributions to our knowledge of flora of China.

Distribution. The genus is distributed in China, India, Laos, Myanmar, Thailand, and Vietnam ( Fig. 6 ).

Figures

FIGURE 1. Maximum likelihood phylogeny of the tribe Millettieae and close relatives based on the concatenated plastid matK and nuclear ITS sequences. The blue fonts indicate samples of Millettia species. The grey cover shows the representative of the new genus Huchimingia and its sister taxa Antheroporum and Ohashia (green fonts). SH-aLRT (SH) and ultrafast bootstrap (BS) support values from maximum likelihood analyses, and posterior probabilities (PP) from Bayesian inference are displayed near the branches (SH/BS/PP).

FIGURE 6. Distribution map of Huchimingia Z.Q. Song & Shi J. Li.