Schistidium memnonium J.Guerra

Guerra, Juan, Cano, María J., Martínez, Mónica, Jiménez, Juan A. & Gallego, M. Teresa, 2021, Schistidium apocarpum complex (Grimmiaceae, Bryophyta) in the Baetic Mountain Ranges, southern Iberian Peninsula, Cryptogamie, Bryologie 20 (5), pp. 45-71 : 61-63

6. Schistidium memnonium J.Guerra

( Fig. 13)

Plant Biosystems (2020).

HABITAT. — Exposed and dry calcareous rocks, from 1300 to 1900 m. Distribution: Figure 14.

DESCRIPTION

Plants

Medium-sized, sometimes small, 1.5-3.1 cm long, forming dense cushions or mats, brownish to blackish.

Leaves

Dense, erect, imbricate, ovate to ovate-triangular, 1.5-2.7(3.2) × 0.5-0.6(0.8) mm.

Hair-point

Straight, decurrent, dense and finely spinulose, to 0.6(0.9) mm long.

Lamina

Smooth, in lower part 1-stratose, occasionally with 2-stratose spots or short striae, in central and upper part varying from 1-stratose to partially 2-stratose in spots and striae; margins sometimes with very short papillae towards the apex near the hair-point, recurved from the base to near the apex on both sides, very rarely almost plane on one side, in lower part mostly 1-2-stratose in 1(2) rows, in upper and central part 2-3-stratose in 1-2 rows, not confluent with the bistratose lamina.

Laminal cells

In upper part isodiametric, rounded, ovate or elliptical, esinuose, (4)5-11 µm long, basal cells occasionally sinuose, 10-45(50) × (4)5-7 µm.

Perichaetial leaves

Oblong, ovate-oblong or ovate-elliptical, acute to subobtuse, sometime abruptly narrowed into the hyaline hair-point, similar in stratosity to vegetative leaves, 2.8-3.4(3.5) × 0.7- 0.8(0.9) mm.

FIG. 14. — Distribution of Schistidium memnonium J.Guerra (★) and Schistidium flaccidum (De Not.) Ochyra (●) in the Baetic System.

Urn

Oblong to oblong-cylindrical, 1.2-1.5(2) × 0.4-0.5(0.6) mm, brown to reddish brown.

Exothecial cells

In central part oblong to long rectangular or long obovate, in lower part around the junction with the seta long rectangular or long obovate, forming a regular pattern like a palisade, stomata absent.

Peristome teeth

(300)400-420 µm long, with 1-2 narrow slits along the median line in the upper part, margins irregular in outline, often with short lateral rami in central part, orange-brown.