Acaulon mediterraneum Limpr.

Larraín, Juan, Cano, María J. & Jiménez, Juan A., 2020, New bryophyte records from the Mediterranean region of Chile, Cryptogamie, Bryologie 20 (11), pp. 131-140 : 135

Acaulon mediterraneum Limpr.

SPECIMENS EXAMINED. — Chile. Región de Coquimbo: Provincia de Choapa, Comuna de Los Vilos, Quebrada Quelón, por Ruta E-37-D entre Quelón y Tilama, en sitio seco con matorral de Adesmia junto al camino, en parte alta de la quebrada, en suelo abierto, 32°06’29.4”S, 71°10’08.2”W, 629 m, 27.VII.2017, J. Larraín 41773B (CONC); Provincia de Limarí, Comuna de Ovalle, por camino al Parque Nacional Fray Jorge (Ruta D-540), algunos kilómetros al W de Punilla, en ladera con matorral denso junto al camino, en suelo abierto, 30°34’03.8”S, 71°36’38.2”W, 427 m, 29.VII.2017, J. Larraín 41968 (CONC). — Región de Valparaíso: Provincia de Valparaíso, Comuna de Valparaíso, Punta Curaumilla, entre Laguna Verde y Quintay, cerca del faro, en acantilados costeros con matorral de Baccharis vernalis , Puya chilensis , Bahia ambrosioides, Eryngium paniculatum y Lobelia polyphylla , en suelo abierto entre arbustos, 33°06’32.9”S, 71°44’02.7”W, 97 m, 29.VI.2016, J. Larraín 40278 (CONC, MUB); Comuna de Quintero, Cerro El Mauco, en la cumbre del cerro, en matorral denso de Baccharis-Lithraea- Quillaja con algunos Myrceugenia rufa dispersos, 32°52’52.0”S, 71°25’38.3”W, 725 m, 14.VIII.2017, J. Larraín 42042 (CONC, MUB). — Región del Biobío: Provincia de Concepción, Comuna de Concepción, Cerro Caracol, on soil among grass in clearing, 36°49’S, 73°02’W, 250 m, 25.IX.2001, R. Ireland & G. Bellolio 31903 (CONC, MO, MUB, NY).

REMARKS

The studied specimens have spores somewhat smaller than those described from European populations, ranging between 20-25 µm, in just a few specimens reaching up to 30 µm, conspicuously echinate. The rest of the morphology perfectly matches the available descriptions of this taxon ( Sérgio 1972;

Stone 1989; Guerra 2006a). The only previous record of the genus for Chile ( Ireland et al. 2006), reported as Acaulon uleanum Müll.Hal. ( Ireland & Bellolio 31903, CONC!), also corresponds to A. mediterraneum , readily separated from A. uleanum by the echinate spores (smooth in A. uleanum : Ule 64, PC!). The later taxon should then be excluded from the bryophyte flora of Chile.

This taxon is rather common during rainy winters in central Chile (June-September), growing in open soil among dry shrubby vegetation or in forest clearings, from sea level to 725 m a.s.l. These are the first records of A. mediterraneum in South America, being previously known from Europe, Macaronesia, Northern Africa, Southwestern Asia ( Turkey), United States (California), and Australia ( Stone 1989; Jiménez et al. 2002; Smith 2004; Dirkse & Losada-Lima 2012; Toren 2015).

A complete description and illustrations of this species are given by Guerra (2006a).