Zygodon viridissimus

(Dickson) Bridel

Bryol. Univ. 1: 592. 1826.

Basionym: Bryum viridissimum Dickson Fasc. Pl. Crypt. Brit. 4: 9, plate 10, fig. 18. 1801
Treatment appears in FNA Volume 28. Treatment on page 81. Mentioned on page 79, 80.

Plants to 2.3 cm. Stem leaves loosely erect and ± spirally twisted to somewhat contorted, sometimes falcate-secund at stem apices when dry, erect-spreading to spreading when moist, lanceolate, narrowly so, elongate-lanceolate, oblong-lanceolate, or linear-lanceolate, 1–2 mm; margins entire or irregularly serrulate or serrate near apex, somewhat wavy; apex acute with gradual apiculus, apiculate, short-apiculate, or short-acuminate; costa ending below apex, abaxial surface covered by quadrate papillose cells distally; basal laminal cells subquadrate to rectangular; distal cells 7–11 µm, papillae 2–4 per cell, walls somewhat thick. Specialized asexual reproduction by clavate, elliptic, or subcylindric gemmae, longitudinal walls present or absent. Sexual condition dioicous. Sporophytes unknown.


V28 127-distribution-map.gif

North America, Mexico, Central America, Europe, w Asia, Africa, Atlantic Islands (Canary Islands).


Varieties 5 (3 in the flora).

Zygodon viridissimus in the flora area includes phenotypes with ovate to elliptic gemmae; narrowly lanceolate, loosely erect leaves; the abaxial surface of the distal 1/3–1/2 of the costa covered with papillose, quadrate cells; dioicous sexual condition; and rudimentary (or no) peristome.

Selected References



1 Leaf margins serrulate at apex. Zygodon viridissimus var. dentatus
1 Leaf margins entire > 2
2 Gemmae with longitudinal septa present; leaves oblong-lanceolate to lanceolate. Zygodon viridissimus var. viridissimus
2 Gemmae with longitudinal septa absent; leaves linear- to elongate-lanceolate. Zygodon viridissimus var. rupestris