Microbryum starckeanum var. starckeanum

Synonyms: Pottia arizonica Wareham
Treatment appears in FNA Volume 27. Treatment on page 629. Mentioned on page 628.

Stem leaves mucronate to short-awned. Capsule stegocarpous, peristome present, usually well-developed but truncate apically. Spores smooth or tuberculate.


Phenology: Capsules mature winter (Jan–Feb).
Habitat: Bare soil, fields
Elevation: low elevations

Distribution

V27 921-distribution-map.gif

Ariz., Calif., Mexico (Baja California), Europe, n Africa, Pacific Islands (New Zealand).

Discussion

A collection from California (Pasadena, “g. 9”, US) has three variants, including var. starckeanum, var. fosbergii, and what is probably best called var. starckeanum but which has an indehiscent operculum, even upon heating in KOH and Pohlstoffe. Another, from Arizona (Pima County, E. B. Bartram 990, Musci Acroc. Bor.-Amer. 572, US) includes var. starckeanum, var. brachyodus, and the indehiscent variant of var. starckeanum. Collections with capsules toward the large end of the size scale, previously called Pottia arizonica, often have entirely smooth spores; commonly, however, some tuberculate and characteristic of M. starckeanum can be identified in at least some capsules. Also, D. F. Chamberlain (1978) described M. starckeanum (as Pottia starckeana) as having smooth or tuberculate spores in his treatment for the British Isles. Capsule contents not differentiating into spores is not uncommon in variants of M. starckeanum, indicating the possibility of occasional hybridization.

Selected References

None.

Lower Taxa

None.
Richard H. Zander +
(Hedwig) R. H. Zander +
Weissia starckeana +
Ariz. +, Calif. +, Mexico (Baja California) +, Europe +, n Africa +  and Pacific Islands (New Zealand). +
low elevations +
Bare soil, fields +
Capsules mature winter (Jan–Feb). +
Bull. Buffalo Soc. Nat. Sci. +
Pottia arizonica +
Microbryum starckeanum var. starckeanum +
Microbryum starckeanum +
variety +