Woodsia obtusa subsp. occidentalis |
Woodsia obtusa subsp. obtusa |
|
---|---|---|
western cliff fern |
bluntlobe cliff fern |
|
Stems | short- to long-creeping, individual branches usually 3–5 mm diam. |
compact to short-creeping, individual branches usually 5–10 mm diam. |
Blade | finely cut, 2-pinnate-pinnatifid. |
coarsely cut and evidently 2-pinnate. |
Spores | averaging 35–42 µm. 2n = 76. |
averaging 42–47 µm. 2n = 152. |
Proximal | pinnules of lower pinnae usually deeply lobed or pinnatifid. |
pinnules of lower pinnae usually shallowly lobed or merely dentate. |
Woodsia obtusa subsp. occidentalis |
Woodsia obtusa subsp. obtusa |
|
Phenology | Sporulating summer–fall. | Sporulating summer–fall. |
Habitat | Cliffs and rocky slopes (rarely terrestrial), found on a variety of substrates but mostly sandstone and granite | Cliffs and rocky slopes (rarely terrestrial), found on a variety of substrates including both granite and limestone |
Elevation | 200–500 m (700–1600 ft) | 0–1000 m (0–3300 ft) |
Distribution |
AR; KS; MO; OK; TX |
AL; AR; CT; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; ON; QC |
Discussion | Woodsia obtusa subsp. occidentalis hybridizes with subsp. obtusa sporadically throughout the region of sympatry; the hybrids are sterile triploids with malformed spores. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
D. F. M. Brown (1964) hypothesized that tetraploid Woodsia obtusa might be an autopolyploid derived from W. oregana. Recent isozyme and spore ornamentation studies indicate, however, that these species are not closely related, and the discovery of a diploid cytotype of W. obtusa suggests a different (albeit autopolyploid) origin for this taxon (M. D. Windham 1993). Tetraploid subsp. obtusa crosses with diploid subsp. occidentalis; the resulting triploids are sterile and have malformed spores. It also hybridizes with W. oregana subsp. cathcartiana to form the sterile tetraploid hybrid known as W. × kansana Brooks. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 2. | FNA vol. 2. |
Parent taxa | ||
Sibling taxa | ||
Name authority | Windham: Contr. Univ. Michigan Herb. 19: 56. (1993) | (Swartz) Torrey |
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