Woodsia |
Woodsia neomexicana |
|||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
cliff-fern, woodsia |
New Mexican cliff fern, New Mexico cliff fern |
|||||||||||||||||||||||||||||||||||||
Habit | Plants usually on rock. | |||||||||||||||||||||||||||||||||||||
Stems | compact to creeping; ascending or erect (rarely horizontal), stolons absent. |
compact, erect to ascending, with few to many persistent petiole bases of unequal lengths; scales mostly uniformly brown but at least some bicolored with dark central stripe and pale brown margins, narrowly lanceolate. |
||||||||||||||||||||||||||||||||||||
Leaves | monomorphic, dying back over winter or sometimes persistent into the next season. |
4–30 × 1.5–6 cm. |
||||||||||||||||||||||||||||||||||||
Petiole | 1/5–3/4 length of blade, base not conspicuously swollen; vascular bundles 2, arranged laterally, ± round or oblong in cross section. |
light brown or straw-colored when mature, occasionally darker at very base, not articulate above base, relatively brittle and easily shattered. |
||||||||||||||||||||||||||||||||||||
Blade | linear to lanceolate or ovate, 1–2-pinnate-pinnatifid, gradually reduced distally to pinnatifid apex, herbaceous. |
linear to lanceolate, usually pinnate-pinnatifid proximally, glabrescent to sparsely glandular, never viscid; glandular hairs with thin stalks and slightly expanded tips; rachis with scattered glandular hairs and rare, hairlike scales. |
||||||||||||||||||||||||||||||||||||
Pinnae | not articulate to rachis, segment margins entire to dentate, not spiny; proximal pinnae somewhat reduced, sessile, bases usually ± equilateral; costae often shallowly grooved adaxially, grooves ± continuous from rachis to costae; indument of glandular (occasionally nonglandular) hairs on both surfaces, rarely absent. |
ovate-deltate to elliptic, longer than wide, abruptly tapered to a rounded or broadly acute apex; largest pinnae with 3–7 pairs of closely spaced pinnules; abaxial and adaxial surfaces glabrescent to sparsely glandular, lacking nonglandular hairs or scales. |
||||||||||||||||||||||||||||||||||||
Indusia | of narrow, filamentous segments, these uniseriate for most of length, composed of ± isodiametric cells, usually surpassing mature sporangia. |
|||||||||||||||||||||||||||||||||||||
Sori | in 1 row between midrib and margin on ultimate segments, round; indusia basal, dissected into several to numerous filamentous or scalelike segments encircling sorus, persistent but often obscure in mature sori. |
|||||||||||||||||||||||||||||||||||||
Spores | brownish, cristate, rarely rugose. |
averaging 44–52 µm. 2n = 152. |
||||||||||||||||||||||||||||||||||||
Pinnules | dentate, often shallowly lobed; margins nonlustrous, thin, with occasional glands, lacking cilia, with 1–2-celled translucent projections on teeth. |
|||||||||||||||||||||||||||||||||||||
Vein(s) | free, simple or forked. |
tips occasionally enlarged to form whitish hydathodes visible adaxially. |
||||||||||||||||||||||||||||||||||||
x | = 38, 39, 41. |
|||||||||||||||||||||||||||||||||||||
Woodsia |
Woodsia neomexicana |
|||||||||||||||||||||||||||||||||||||
Phenology | Sporulating summer–fall. | |||||||||||||||||||||||||||||||||||||
Habitat | Cliffs and rocky slopes, usually on sandstone or igneous substrates | |||||||||||||||||||||||||||||||||||||
Elevation | 300–3500 m (1000–11500 ft) | |||||||||||||||||||||||||||||||||||||
Distribution |
Mostly north temperate regions and higher elevations in the tropics |
AZ; CO; NM; OK; SD; TX
|
||||||||||||||||||||||||||||||||||||
Discussion | Woodsia is a well-marked genus; its morphology and chromosome base number (x = 41) provide evidence of relationships to the dryopteroid ferns. Most authors consider Cystopteris to be its closest ally, and the two genera are often confused in herbarium collections. The resemblance is superficial in many ways, however, and Woodsia is easily distinguished from Cystopteris by its persistent petiole bases, multilobed indusia, and obscure veins that end in hydathodes before reaching the leaf margin. The North American species of Woodsia fall into two natural groups that might be recognized as subgenera. Woodsia ilvensis, W. glabella, and W. alpina have articulate petioles, indusial segments that are uniseriate throughout and composed of cells that are much longer than wide, entire or crenate pinnules, strictly concolored stem scales, and chromosome base numbers of 39–41. They are circumboreal in distribution and show clear affinities to species found only in Eurasia. The remainder of the North American taxa have petioles that are not articulate, indusial segments that are multiseriate at the base and composed of cells that are isodiametric or slightly longer than wide, dentate pinnules, often bicolored stem scales, and a chromosome base number of 38. All of these species are endemic to the New World and probably represent a distinct lineage within the genus. Hybridization is common within these natural groups, but intergroup hybrids are relatively rare. Species ca. 30 (10 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Woodsia neomexicana traditionally has been identified as W. mexicana. Both taxa are tetraploid and may share one parent (M. D. Windham 1993); W. neomexicana is separated from typical W. mexicana by its completely filamentous indusial segments, reduced glandularity, and more northerly distribution. Isozyme data suggest that W. neomexicana is an allotetraploid hybrid between W. phillipsii and the diploid progenitor of W. oregana subsp. cathcartiana (M. D. Windham 1993). As with all allopolyploids, W. neomexicana can vary in the direction of either parent, and some plants (especially those resembling W. phillipsii) can be difficult to identify. All characters except those controlled directly by ploidy level show this tendency, and spore size remains the most dependable character for distinguishing W. phillipsii and W. neomexicana. This species hybridizes with W. oregana subsp. cathcartiana and W. phillipsii to produce sterile tetraploids and triploids, respectively. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||||||||||||||||||||||||||||||||||
Key |
|
|||||||||||||||||||||||||||||||||||||
Source | FNA vol. 2. | FNA vol. 2. | ||||||||||||||||||||||||||||||||||||
Parent taxa | ||||||||||||||||||||||||||||||||||||||
Sibling taxa | ||||||||||||||||||||||||||||||||||||||
Subordinate taxa | ||||||||||||||||||||||||||||||||||||||
Name authority | R. Brown: Prodr. 158. (1810) | Windham: Contr. Univ. Michigan Herb. 19: 52. (1993) | ||||||||||||||||||||||||||||||||||||
Web links |
|