Riccardia chamedryfolia (With.) Grolle

Reeb, Catherine, Bernard, Elisabeth Lavocat & Gradstein, S. Robbert, 2022, An integrative taxonomic revision of Aneuraceae H. Klinggr. (Marchantiophyta) from Guadeloupe and Martinique, French West Indies, Cryptogamie, Bryologie 20 (8), pp. 135-152 : 141

Riccardia chamedryfolia (With.) Grolle

Jungermannia chamedryfolia With., A Botanical Arrangement of all the Vegetables Naturally Growing in Great Britain 2: 699 (1776). —

Riccardia chamedryfolia (With.) Grolle, Transactions of the British Bryological Society 5 (4): 772 (1969). — Type: England ( Grolle 1976).

Jungermannia sinuata Dicks. , Fasciculus Plantarum Cryptogamicarum Britanniae 2: 16 (1790), nom. illeg. — Jungermannia multifida var. sinuata Hook. , British Jungermanniae : tab. 45 (1813). — Riccardia sinuata (Hook.) Trevis., Memorie della Reale Istituto Lombardo di Scienze e Lettere Serie 3, 4: 431 (1877). — Type: England.

SPECIMENS EXAMINED FROM THE FRENCH ANTILLES. — Guadeloupe. Aire de Beausoleil, Saint-Claude, 16°01’53”N, 61°40’50”W, 750 m, 08.IV.2009, Lavocat Bernard 1126; Carbet Falls trail, 16°02’40”N, 61°38’31”W, 640 m, 27.VI.2017, Lavocat Bernard 17604; La Madeleine,Trois-Rivières, 16°00’30”N, 61°38’00”W, 640 m, 22.VIII.2016, Lavocat Bernard 16854; Sentier Mamelle Pigeon, 16°10’N, 61°44’W, 580 m, 08.II.2013, CR13G53, CR13G56bis.

Martinique. Mount Pelée, trail of Grande Savane, 14°48’36”N, 61°10’14”W, 1160 m, 09.VIII.2012, Lavocat Bernard 1744, 1760.

DISTRIBUTION AND HABITAT. — Widespread in temperate regions of the Northern Hemisphere, scattered in the Tropics. In the Neotropics recorded from the West Indies, Brazil and the northern Andes ( Gradstein & Reeb 2018b), growing on bark and rock in humid habitats at middle to high elevation. In the West Indies the species is known from Cuba (Meenks unpubl.), Saba (Buck 52491, NY; det. SRGr), Jamaica ( Söderström et al. 2011), Guadeloupe ( Pagán 1942 as R. sinuata ; Lavocat Bernard & Schäfer-Verwimp 2011), Martinique ( Lavocat Bernard 2018) and possibly from further islands.

ILLUSTRATIONS. — Gradstein & Reeb (2018b), Reeb & Gradstein (2020).

REMARKS

Riccardia chamaedryfolia is a rather widespread, autoicous species that is recognized by the prostrate, 0.3-0.6 mm wide and 1-2 cm long, irregularly 1(-2)-pinnate thalli without stolons, a 4-7(-8) cells thick, plano-convex to concavo-convex axis without wing, and the linear to tongue-shaped, narrowly winged branches, the wings 1-2(-3) cells wide. The epidermis cells are scarcely smaller than inner thallus cells and oil bodies are present in all epidermis cells ( Gradstein & Reeb 2018b; Reeb & Gradstein 2020). The species is highly polymorphic and may be confused with R. cataractarum , a semi-aquatic South American species that was recently recorded from the French Antilles ( Lavocat Bernard & Reeb 2016; Lavocat Bernard 2018). The latter species, however, is dioicous and has an axis that is biconvex in the lower half (plano-convex above), with long ± wingless vegetative branches and broadly winged sexual branches ( Gradstein & Reeb 2018b; Gradstein 2021). When sterile, separation of the two species may be difficult although R. chamedryfolia has mostly plano- to concavo-convex thalli (rarely biconvex in older portions of plants from Great Britain; Paton 1999). Molecular species delimitation shows conserved sequences for the amplified markers of R. chamedryfolia ( Rabeau et al. 2017) . In the present study the R. chamedryfolia cluster is very well defined with each method used ( Fig. 1 ).

Figures

FIG. 1. — Species delimitation results plotted in regards of the Bayesian tree obtained with Beast for the GMYC analysis. Posterior probabilities> 0.9 were kept. The number for species proposed by each method is given in the highest line. Final species hypothesis are plotted on the right. Specimens from West Indies are colored in red. Abbreviations: ECU, Ecuador; REU, La Réunion; FRA, France; MAD, Madagascar; GLP, Guadeloupe; SHN, Saint Helena; MTQ, Martinique; USA, United States; COM, Comoros; IDN, Indonesia; UGA, Uganda; BES, Saba.