TABLE 2 in Pterygoneurum sampaianum (Guim.) Guim.: range extension to Africa, first mentions in France, confirmation of specific status and improved morphological circumscription

TABLE 2. — Morphological comparison between Pterygoneurum sampaianum (Guim.) Guim. and P. ovatum (Hedw.) Dixon.
Morphological charactersPterygoneurum sampaianum (Guim.) Guim.Pterygoneurum ovatum (Hedw.) DixonGametophyteGeneral habitIsolated individuals.Small tufts, or extensive carpets.ShootShortly bulbiform, <2 mm high.Stem elongated, 2-7 mm high.RhizoidsLess than 10, tuberous, 36-50 µm thick.Numerous, 25-30 (40) µm wide.Proximal leavesReduced, poorly chlorophyllose and awn-less.Normal, chlorophyllose, bearing a normal hair-point.Distal leavesDeeply concave to convolute, wider than longer; 0.7- 0.9 ×0.7-0.8 mm (rarely longer than wider; 0.4-0.5× 0.8- 0.9 mm).Concave to carinate, not convolute, longer than wide; 0.6- 1.2× 0.8-1.4 mm.Hair-pointMostly absent or short, or longer (<400 µm), smooth.Constantly long (<2500 µm), denticulate in the distal part.Basal marginal cellsForming a hyaline border of strongly differentiated cells (longer and thinner) or no border differentiated.Not forming a border (or marginal cells progressively slightly differentiated).Basal cells15-22× 18-45 µm.12-21 ×28-71 µm.Median cells8-15 × 8-20 µm.11-18 ×13-35 µm.Apical cellsOften a majority of cells hyaline, 7-13 ×8-18 µm.Not hyaline, or a few cells hyaline, 3-12 ×10-15 µm.Distal marginOften denticulate.Entire, or rarely a few denticulations.Anatomy of nerveGuide cells poorly differentiated; no hydroids; dorsal stereid poorly differentiated.3-4 guide cells differentiated; hydroid strand; dorsal stereid poorly differentiated.Ventral lamellae2(-3); 5-15 cells high.2-4; 8-22 cells high.SporophyteSeta<2.5 mm.<3.5 mm.ThecaCylindrical to cupulate, <890 µm long; exothecium faintly wrinckled when dry.Longly cylindrical to ovoid, <2000 µm long; deeply wrinckled with anastomoses when dry.Spores35-58 µm accross diameter.23-35 µm accross diameter.