Aligrimmia peruviana R. S. Williams 1903

Aligrimmia peruviana R.S. Williams Bulletin of the New York Botanical Garden 3 (9): 124 (1903). SPECIMEN EXAMINED. — Mexico. Estado de México, Nevado de Toluca, 19°07’N, 99°45’W, 9.IX.2018, in alpine area, on exposed moist rock, Romero 47 (MEXU). DISTRIBUTION. — Aligrimmia peruviana is known from Peru and Argentina. J. C. Solomon collected a specimen in Peru in 1977, and M. J. Cano and M. Alonso obtained two samples in Argentina in 2008, according to records cited in Tropicos. REMARKS Aligrimmia peruviana R.S. Williams was described as a new genus and species more than a hundred years ago (Williams 1903). Deguchi (1987) and Murray (1984) described and illustrated its peculiar morphology based on the type specimen which, until recently, was the only herbarium material available for this taxon. In 2018 Jorge Romero, a student searching for moss tardigrades collected a mixed sample containing several stems of A. peruviana. This material shows the same gametophytic features as the Peruvian plants but bear no sporophytes. The fleshy ovate-oblong leaves are loosely imbricate when dry, with a sub-cucullate apex, and erect margins partly covering the lamellae; the costa is broad, c. 100 µm at base, covered by 3-7 cell high lamellae in the distal half. In transverse section, the lamina is mostly unistratose; the costa has a dorsal stereid band covered by two layers of guide cells one of which extends over the lamina and bears lamellae as well. Other features are described and illustrated by Deguchi (1987) and Murray (1984).