THE BRYOLOGIST. 



Vol. V, January, 1902. No. i. 



LEUCODON SCHWAEQR. Suppl. 1. pt. 2:1, 1816. 



By a. J. Grout. 



The various species of Leucodon grow almost exclusively on the bark of 

 deciduous trees, very rarely are any found on dry rocks. The Leucodons 

 are seemingly able to do without moisture for considerable periods as they 

 rarely or never grow at the base of trees, but at a height of five or six 'feet 

 and above. The main stems are long, slender, branching, almost filiform, 

 with minute leaves and abundant rhizoids. The secondary stems are numer- 

 ous, suberect, horizontal, or hanging downward and curved outward, usually 

 julaceous and nearly simple; paraphyllia lacking. Leaves many ranked, 

 concave, with margins recurved below, ecostate, entire or slightly serrulate 

 at apex, closely appressed when dry, spreading when moist; leaf cells 

 strongly incrassate; several rows of marginal cells are roundish- quadrate ; 

 the lower median, linear, gradually changing to oval at the apex: basal cells 

 often brownish or reddish yellow. Dioicous. Calyptra cucuUate, often at- 

 tached below the capsule by the connate base. Capsules exserted or emer- 

 gent, erect and symmetrical; peristome apparently simple, teeth 16, 

 articulate and papillose, bifid or occasionally trind: inner peristome reduced 

 to a narrow inconspicuous membrane. 



We have three species, only one of which, L. sciuroides, is European. 

 There is considerable difference of opinion as to what other genera of mosses 

 should be grouped with Leucodon. Cryphea and Antitricha are apparently 

 closely related genera. More careful study of its development and structure 

 is needed to determine whether its natural relationship is with the Necker- 

 acese or the Hypnacese. 



Leucodon julaceus (Hedw.) Sulliv. This species is typically south- 

 ern, extendmg north to Southern New England and correspond- 

 ing latitudes of the Eastern United States. The secondary stems 

 are typically shorter than in the other two species, the branches 

 very terete, julaceous when dry: the leaves closely appressed and 

 imbricate, not at all secund, ovate-elliptical, abruptly short acuminate, very 

 convace, scarcely plicate, serrulate at apex. Upper median leaf cells 

 markedly shorter and broader than in the other two species. Capsule long 

 exserted as in L. sciuroides\ annulus none; teeth bifid at apex. 



Easily recognized by its perfectly terete stems and smaller, scarcely 

 plicate, abruptly acuminate leaves. 



Leucodon sciuroides (L. ) Schwaegr. Forming tufts or mats of brownish 

 green, lighter green at the tips of the secondary stems, which are terete 

 and. julaceous. more or less drooping and curved upwards at the ends, 

 rarely 5cm. long, usually not over 3cm., frequently producing such a great 

 The October Bryologist was issued October 5th, 1901. 



