Hennediella

Introduction

Hennediella Paris is a small genus of the family Pottiaceae distributed throughout much of the world from 81ºN in the Arctic to 78ºS in the Antarctic, although its highest diversity is found in the Southern Hemisphere. The species of this genus occur from near the sea level to 5000 m, growing mainly on soil or on ledges, taluses, walls and rocks with accumulated soils. The world revision of Cano (2008) recognized 17 taxa.
The genus as presently defined includes small plants characterized mainly by leaves edged with cells that are different in shape, usually rectangular to linear, in 1-4 strata, less papillose and thicker walled than the inner cells, leaf margins plane, occasionally slightly recurved, mostly denticulate to dentate at least close to the apex, costa usually with dorsal and ventral surface cells differentiated, one band of dorsal stereids usually semicircular, surface of the laminal cells frequently plane and KOH color reaction orange to reddish. The sporophyte varies from emergent capsules with long seta and peristomes of 32 spirally teeth with a long basal membrane to short seta with capsules immersed and gymnostomous (Zander 1993, Cano 2008).