Miersia raucoana J.E. Sepulveda & Nic. Garcia, 2022

Garcia, Nicolas, Cuevas, Claudia, Sepulveda, Joaquin E., Cadiz-Veliz, Aron & Roman, Maria Jose, 2022, Two new species of Miersia and their phylogenetic placements alongside the recently described M. putaendensis (Gilliesieae, Allioideae, Amaryllidaceae), PhytoKeys 211, pp. 107-124 : 107

Miersia raucoana J.E. Sepulveda & Nic. Garcia sp. nov.

Figs 5 , 6

Diagnosis.

Miersia raucoana differs from Miersia tenuiseta Ravenna by the lack of tepaliferous appendages or tiny and awl-shaped, <0.5 mm long, if present (vs. 6 conspicuous filiform, bifid tepaliferous appendages), a slightly zygomorphic conical staminal tube (vs. strongly zygomorphic urceolate staminal tube), and 3-5 purple longitudinal stripes in each tepal (vs. none or single broad central longitudinal stripe).

Type.

Chile. Región del Maule: Provincia de Curicó, Comuna de Rauco, quebrada Guayacán, 535 m a.s.l., 6 July 2021, N. García, J. Sepúlveda, A. Cádiz-Véliz, C. Soto & M. Tobar 6139 (holotype: EIF 14824 ; isotypes: CONC, JBN, SGO) .

Description.

Terrestrial saxicolous herbs. Bulbs subglobose to ovoid, 10-12 × 7-10 mm, external cataphylls light brown. Leaves 3-4, linear, 8-23 × 0.08-0.15 cm. Scapes 2-3, cylindrical, hollow, 10-40 × ca. 0.8 mm. Spathe 2-valvate, herbaceous, lanceolate, 10-10.5 × 3-3.5 mm, fused on their basal ¼ (~2.5 mm), veins purple. Inflorescences a pseudo-umbel with 2-5 slightly zygomorphic flowers; pedicels unequal, 1.5-2.0 cm long. Tepals 6, free, membranous, creamy white to yellowish (in dry specimens) with 3-5 purple longitudinal stripes each (exceptionally without stripes), lanceolate to obovate, acute, straight to slightly reflexed apically, outer 8-9 × 3.5 mm, inner 7-8 × 3.0-3.5 mm. Tepaliferous appendages absent or inconspicuous, awl-shaped, purple, <0.5 mm long. Stamens 6, filaments 0.5-0.8 mm long, diminishing in length towards the downward side of the flower, adnate internally to the staminal tube; staminal tube conical, apex narrowly tubular (ca. 0.8 × 0.5 mm), slightly zygomorphic, purple, papillose, 3-4 × 2.5-3.0 mm; anthers 6, yellow (purple when dry), ca. 0.3-0.4 mm long, exerted. Ovary superior, spherical to obovoid, 1.0-1.5 mm long, trilocular, 10 ovules per locule, biseriate; style straight to ascending, 1.5-2.0 mm long, reaching the anthers or exerted in mature flowers; stigma capitate. Capsules obovoid to spherical, 3-valved, 8 × 6.5 mm, 13-14. Seeds obovoid, 1.6-2.0 × 1.0-1.4 mm, testa reticulate, 13-14 per capsule.

Distribution and habitat.

Miersia raucoana was originally recorded in a rocky east- to northeast-facing slope in the coastal mountain range of Rauco (~34.9°S), Maule Region. During the review process of this article, it was also recorded around the La Palmilla dam, located ca. 3 km north of the typical locality. It can be found growing in rock crevices or in the base of rocky outcrops, between 240 and 540 m a.s.l. The surrounding vegetation corresponds to a sclerophyllous arborescent scrub, where the most abundant species are Lithraea caustica (Molina) Hook. & Arn, Peumus boldus Molina, Vachellia caven (Molina) Seigler & Ebinger, Retanilla trinervia Hook. & Arn., Chusquea cumingii Nees, and Leucostele chiloensis (Colla) Schlumpb.

Phenology.

Miersia raucoana has been recorded in flowers from May to early August. Fruits have been recorded in late July and throughout August.

Etymology.

The specific epithet refers to Rauco, a municipality located to the west of the city of Curicó in the Maule region of Chile.

Vernacular name.

We propose to name this species as " miersia de Rauco ".

Conservation status.

Miersia raucoana can be considered Critically Endangered (CR) under criteria B2ab(iii), because its area of occupancy is <10 km2, with an estimated 1.8 km2. Only a single population scattered throughout the latter area, with <1,000 mature individuals, has been recorded despite sampling efforts in surrounding areas in suitable seasons and habitats. In addition, the area is at risk of forest fires and is subject to land use change for agricultural crops, motorized sporting activities, and goat and cattle ranching.

Additional specimens examined

(paratypes). CHILE. Región del Maule: Provincia de Curicó, Comuna de Rauco, quebrada Guayacán, 535 m a.s.l., 12 August 2020, J. Sepúlveda s.n. (EIF) .

Figures

Figure 5. Miersia raucoana J. E. Sepulveda & Nic. Garcia A front view of flower B detail of flower lacking appendages C lateral view of flowers showing tiny tepaliferous appendages D inmature fruit E habit F habitat. Scale bars: 5 mm. Photos by Jose Luis Inostroza (A, D), Matias Tobar (B), Joaquin Sepulveda (C, E, F).

Figure 6. Miersia raucoana J. E. Sepulveda & Nic. Garcia A habit B flower (frontal view) C staminal tube (lateral view) D seed E fruit (apical view) F fruit (lateral view). Illustration by Aron Cadiz-Veliz.