Notes on the Erpodiaceae of North America, with a Description of Solmsiella kurzii, sp. nov.

Abstract

The type species of the genus Erpodium, E. domingense (Brid.) C. Mull., was originally described from Santo Domingo, in I827. Since then, the reported range of this species has been extended to several of the other West Indian islands; also to Yucatan, Guatemala, and Texas (Steere, I934), and three additional North American species of have been described. The limited distribution and inconspicuousness of these small plants is well illustrated by the fact that two, E. (Aust.) Aust. and E. cubense E. G. Britt., have never been collected since their original discovery. The fourth species, E. Pringlei E. G. Britt., has been recorded only from a somewhat restricted area in Mexico. The surprising occurrence of Venturiella sinensis (Vent.) C. Mull. in Texas was recently reported (Steyermark and Moore, I933; Bartram, I934). Up to the present time, these five species have represented the Erpodiaceae in North America. An interesting moss belonging to the Erpodiaceae was recently received for study through the kindness of Dr. A. W. Evans. The collection, tentatively labelled Erpodium biseriatum had been made at Lake Miccosukee, Florida, by Dr. Herman Kurz. The specimens, which bore only a few sporophytes in various stages of preservation, showed a well developed foliar dimorphism, which is an unusual and interesting character in mosses. The leaves were complanate, and in four rows. Those on the ventral side were only about one half the size of the dorsal leaves, which were nearly plane, except for the inflexed lower margin. addition, the capsule and seta were exserted, and the annulus was completely undifferentiated. These rather clear-cut characters all point away from the genus Erpodium, which has little or no foliar dimorphism, very concave or hollow leaves, completely or partly immersed capsules, and a wide and persistent annulus. The characters of Dr. Kurz's collection seem to indicate rather conclusively the genus Solmsiella, in which two species, S. ceylonica (Mitt.) C. Muill. and S. paraguayensis Broth., are currently recognized. One of the important diagnostic characters which Muller (I884) stressed in the description of the genus Solmsiella is the nonplicate and entire calyptra, which in is plicate and serrate on the upper part of the folds. Although the calyptra is unfortunately lacking in this material, its generic position is made no less certain, since in the original descriptions of the other species of Solmsiella, vegetative characters alone were used as the distinguishing features. For instance, Mitten's ceylonicum, which is now the type species of Solmsiella, was separated principally on the basis of foliar dimorphy from domingense, at that time the only known species of and still the type species. Mitten (I873) says: In E. domingense the leaves are compressed and rather densely inserted; those on the underside of the