Kiaeria I. Hagen, 1915.

Kiaeria differs from the closely related Arctoa primarily in capsule morphology. Kiaeria has a somewhat inclined and asymmetric capsule with a small struma; Arctoa has an erect non-strumose capsule that is sulcate and strangulate when old and deoperculate. Both are plants of montane and alpine rocks in the north of the state. Both are autoicous and usually with sporophytes. Identification of Kiaeria depends strongly on the placement of the perigonia. If one has perichaetial or sporophytic material, a search of leaf axils very near the perichaetium should reveal the perigonia in K. falcata and K. starkei. Failure to find such perigonia signals the probability of K. blyttii, a species typically with perigonia on the apex of a separate small branch.

Key to Kiaeria Etc.

The plants in the following key are small and erect with falcate leaves and with the costa excurrent in a narrowly subulate apex. The leaf margin is entire to faintly serrulate and the costa is without stereid bands.

Species included in this key are in Dicranaceae, except Blindia (Seligeriaceae):
Arctoa hyperborea (Withering) Bruch & W. P. Schimper, not known from CA
Arctoa fulvella (Dickson) Bruch & W. P. Schimper
Blindia acuta (Hedwig) Bruch & W. P. Schimper
Kiaeria blyttii (Bruch & W. P. Schimper) Brotherus
Kiaeria falcata (Hedwig) I. Hagen
Kiaeria starkei (Weber & D. Mohr) I. Hagen

In keeping with the gametophytic emphasis of this work, we have used leaf characters, particularly alar features, but we use them while issuing a strong caveat. The majority of examples of Kiaeria are placed easily, but a large minority seem to exhibit intermediate features.

A. Auricle present and formed of thin-walled, brownish cells that are often left on stem with careless dissection; marginal cells narrowly rectangular to linear; median laminal cells 6-10:1 .....Blindia: B. acuta
A. Leaves with a non-auriculate base but with alar region more less distinct; marginal cells of median lamina short rectangular with the interior laminal cells seldom more than 5:1 .....B

B. Capsule strongly ribbed when dry, erect, not strumose, with exothecial cells short and thick-walled .....C
B. Capsule not, or lightly, sulcate, inclined and strumose with exothecial cells various .....D

C. Laminal cells above the leaf middle mostly 1-2:1; leaves 3-5 mm long; peristome teeth erect when dry .....Arctoa: A. hyperborea not known from CA
C. Laminal cells above leaf middle rectangular, 2-5:1; leaves 2-3 mm long; peristome teeth when dry widely spreading from mouth of capsule .....Arctoa: A. fulvella

D. Cells of alar region sharply demarcated, somewhat inflated; perigonium mostly within a few cells of perichaetium; exothecial cells more than 4:1 with lumen wall ratio about 5-8:1 .....Kiaeria starkei
D. Cells of alar region not very inflated with only a gradual transition toward the median laminal region; perigonium and exothecial cells various .....E

E. Leaves somewhat distorted to almost crispate when dry; perigonia either near base of perichaetial stem or on a separate branch; capsule not at all sulcate; exothecial cells more than 4:1 with lumen wall ratio about 5-8:1 .....Kiaeria blyttii
E. Leaves falcate but not at all distorted when dry; perigonium mostly within a few cells of perichaetium; capsule often very lightly sulcate when old and deoperculate; exothecial cells less than 2:1 with lumen/wall ratio less than 4:1 .....Kiaeria falcata