Hedwigia Palisot de Beauvois, 1804.

Hedwigia detonsa, photo by Wilson

In California, we have two genera of the Hedwigiaceae, and these both are immediately recognized as petricolous mosses with hyaline awns and deeply concave, ecostate leaves on a julaceous stem. Those few characters allow immediate and unambiguous recognition. Hedwigia has sessile capsules.

Key to Hedwigia Etc.

The mosses treated in this key are julaceous with ecostate leaves and high papillose median laminal cells. With the exception of Braunia, these plants have hyaline awns.

Species included in this key are all in Hedwigiaceae:
Braunia secunda (W. J. Hooker) Bruch & W. P. Schimper in Bruch & W. P. Schimper, not known from CA
Hedwigia ciliata (Hedwig) Palisot de Beauvois
Hedwigia detonsa (Howe) W. R. Buck & Norris
Hedwigia stellata Hedenäs
Pseudobraunia californica (Lesquereux) Brotherus

A. Leaves without hyaline awns; base of leaf with small plications .....Braunia: B. secunda not known from CA
A. Leaves with hyaline awns, wrinkled but not plicate when dry .....B

B. Median leaf cells with unbranched papillae that appear circular to short-elliptic from surface view; awn long and flexuose, often caducous in older leaves, uniseriate for most of its length; capsule exserted .....Pseudobraunia: P. californica
B. Median cells with branched papillae that appear stellate in surface view; awn decurrent and not flexuose or caducous, several cells broad to near the apex; capsules immersed .....C

C. Abaxial surface of some of the upper laminal cells with more than 2 papillae; apical cell of awn usually truncate and coronate papillose .....Hedwigia ciliata
C. Abaxial surface of upper laminal cells consistently with only 1-2 papillae; apical cell of awn pointed with papillae seriate .....D

D. Perichaetial leaves without marginal cilia; awns of vegetative leaves serrulate or even entire, never spinose on dorsal surfaces; the perichaetial leaves abruptly larger than the vegetative leaves of adjacent branches .....Hedwigia detonsa
D. Perichaetial leaves with ciliate margins; dry plant with awns of vegetative leaves erect or nearly so; awns of vegetative leaves with spinose teeth both on the margins and on the dorsal surfaces; the large perichaetial leaves only gradually differentiated from the smaller vegetative leaves .....Hedwigia stellata