Seligeria Bruch & W. P. Schimper, 1846

Seligeria is recognizable primarily by the habitat. Calcareous seepages should be closely investigated for the extremely small plants of this genus. We expect that it will be found in some of the basaltic areas of the Modoc Plateau of northeastern California. Many of the springs that emerge from these lava plateaus are heavily charged with calcium bicarbonate which precipitates as small tufa deposits as the water emerges. These springs tend to be some of the most reliable places for calciphilous bryophytes in the state of California.

Key to Seligeria Etc.

Treated in this section are the smallest acrocarpous, epipetric mosses, none of which we have yet found in California. These mosses are so small as to become visible only when one looks across the edge of the rocks on which they are growing. They are too small to be easily seen without sporophytes, and so the key that follows primarily emphasizes sporophytic characters. The sporophytes are exserted on short, straight or arcuate setae. These plants grow exclusively on rocks. Seligeria is exclusively on calcareous substrates, while Brachydontium is exclusively on siliceous substrates. The unrelated Campylostelium and Tetrodontium are also keyed here because of their very small size.

Species included in this key are in Seligeriaceae, except Campylostelium (Ptychomitriaceae), and Tetrodontium (Tetraphidaceae):
Brachydontium olympicum (E. Britton) McIntosh & Spence, not known from CA
Brachydontium trichodes (Weber) Milde, not known from CA
Campylostelium saxicola (Weber & D. Mohr) Bruch & W. P. Schimper, not known from CA
Seligeria campylopoda Kindberg in Macoun, not known from CA
Seligeria donniana (Smith) C. Müller Hal., not known from CA
Seligeria recurvata (Hedwig) Bruch & W. P. Schimper, not known from CA
Tetrodontium brownianum (Dickson) Schwägrichen, not known from CA
Tetrodontium repandum (Funck in Sturm) Schwägrichen, not known from CA

A. Plant with an erect seta .....B
A. Plant with an arcuate seta .....D

B. Leaves with costa absent or ending before the apex; peristome teeth 4, rigidly erect; calyptra mitrate and lightly plicate .....C
B. Leaves with costa percurrent to excurrent in a narrow subula; peristome teeth 16 or absent; calyptra cucullate .....E

C. Perichaetial leaves costate to above middle, ovate and shortly acuminate, protonematal flaps to 2 mm long; flagelliform shoots present .....Tetrodontium: T. brownianum not known from CA
C. Perichaetial leaves ligulate; ecostate; protonematal flaps to 0.5 mm long; flagelliform shoots frequent .....Tetrodontium: T. repandum not known from CA

D. Capsule sulcate when mature and dry: plant on siliceous rocks, often granites or basalts .....Brachydontium: B. trichodes not known from CA
D. Capsule smooth when mature and dry; plant on calcareous seeps .....Seligeria donniana not known from CA

E. Costa excurrent and filling up to 1/6 of the length of the leaf apex .....Seligeria recurvata not known from CA
E. Costa percurrent in the mostly subulate apex .....F

F. Plant growing on calcareous seeps; leaves oblong-lanceolate, distally obtuse .....Seligeria campylopoda not known from CA
F. Plant growing on siliceous rock, mostly only periodically moist; leaves narrowly subulate .....G

G. Seta shorter than the perichaetial leaves; capsule gymnostomous .....Brachydontium: B. olympicum not known from CA
G. Seta elevating capsule above the perichaetial leaves; capsule with 16 narrow peristome teeth .....Campylostelium: C. saxicola not known from CA