Mazus fruticosus Bo Li, D.G. Zhang & C.L. Xiang, sp. nov.

Xiang, Chun-Lei, Pan, Hong-Li, Min, Dao-Zhang, Zhang, Dai-Gui, Zhao, Fei, Liu, Bing & Li, Bo, 2021, Rediscovery of Mazus lanceifolius reveals a new genus and a new species in Mazaceae, PhytoKeys 171, pp. 1-24 : 1

Mazus fruticosus Bo Li, D.G. Zhang & C.L. Xiang, sp. nov. Fig. 2

Type.

China. Hubei Province: Shennongjia Forestry District, Laoyaya to Luoboxi, on rocky cliffs, 110°29'07.98"N, 31°19'23.92"E, 1282 m elev., 6 June 2012, D.G. Zhang zdg6673 (Holotype: JIU!).

Diagnosis.

Mazus fruticosus differs from all other conspecific taxa by being a shrub with numerous and much branched stems and having opposite to subopposite leathery leaves that are acutely serrate on apical half.

Description.

Shrubs, 25-55 cm tall. Stems woody, numerous branched, old stems greyish brown, terete, leafless, glabrous, young stems and branchlets brown, densely puberulent. Leaves nearly fascicled on the top of branchlet, opposite to subopposite, subsessile; lamina lanceolate, leathery, 3.5-5.5 × 0.7-1.1 cm, adaxially green, subglabrous to sparsely puberulent, abaxially light green, subglabrous, puberulent on veins, apex acute to acuminate, base cuneate, margin acutely serrate on apical half; midrib conspicuous abaxially, lateral veins inconspicuous; petioles nearly absent, densely puberulent. Racemes terminal, ascending to 7.5 cm long, lax, multiflowered; pedicels slender, 1-1.5 cm long, puberulent; bracts narrowly lanceolate, 3-4 mm long, puberulent. Calyces broadly campanulate, ca. 5 mm long, slightly enlarged in fruit, 5-veined, pubescent outside, pubescent to subglabrous inside; lobes 5, broadly triangular, as long as tube, apex acute, midrib conspicuous, lateral veins inconspicuous. Corolla purple, dotted yellow on palate, 1.6-1.9 cm long, puberulent to subglabrous outside, tube cylindric, 1.1-1.3 cm long, exserted from calyx; limb 2-lipped, upper lip bilobed, erect, lobes triangular ovate; lower lip trilobed, middle lobe narrowly ovate, ca. 3 mm long, smaller than lateral lobes, lateral lobes spreading away from middle lobe, broadly ovate to rectangular; palate comprising 2 longitudinal elevations extending from point of filament fusion to base of lower lobes, with sparse erect hairs. Stamens 4, didynamous, glabrous, inserted at the same level in distal part of tube, included; anterior pair longer, curved, appressed to corolla tube, posterior pair spreading; anthers bithecal, positioned adjacent to corolla tube on upper lip; filaments filiform, glabrous. Styles 1.4-1.7 cm long, included, exserted beyond anthers, stigma 2-lamellate. Capsule globose, ca. 4 mm in diam, apex rounded, included by persistent calyx.

Etymology.

The epithet of the new species refers to its shrubby habit.

Common name

(assigned here). Guan Zhuang Tong Quan Cao (灌状通泉草; Chinese name).

Distribution and habitat.

Mazus fruticosus is currently known only from Shenlongjia Forest District in Hubei Province, central China. It frequently occurs on rocky cliffs or near evergreen mixed forests at an elevation of 1100-1250 m.

Additional specimens examined.

China. Hubei Province: Shennongjia Forestry District, 29 March 2012, D.G. Zhang y1071 (JIU!); 11 May 2012, D.G. Zhang zdg00023 (JIU!); 17 August 2012, D.G. Zhang 00006 (JIU!); 21 May 2013, D.G. Zhang 130521012 (JIU!); 23 April 2015, D.G. Zhang 0423007 (JIU!).

Figures

Figure 2. Mazus fruticosus A voucher of " Mazus lanceifolius " sampled in Deng et al. (2019), deposited at JIU (the herbarium of Jishou University, Hu'nan, China) B habit and habitat C leaves D flower in frontal view, showing morphology of its lower lips E flower in frontal view, showing morphology of its upper lips F flowers in lateral view. Scale bars: 2 cm (C); 0.5 cm (D, E, F).