Flora of North America species comparison

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Polystichum dudleyi

Polystichum lemmonii

Dudley's sword fern

Lemmon's holly fern, Lemmon's sword fern, Shasta fern, Shasta sword fern
Stems

erect.

decumbent to ascending.
Leaves

monomorphic, arching, 2–10 dm;

bulblets absent.

erect, 1–3.5 dm;

bulblets absent.
Petiole

1/5–1/3 length of leaf, densely scaly;

scales light brown, gradually diminishing in size distally.

1/5–1/4 length of leaf, sparsely scaly;

scales pale tan, abruptly diminishing in size distally.
Blade

broadly lanceolate, 2-pinnate, base not narrowed.

narrowly lanceolate, 2-pinnate, scarcely narrowed at base.
Pinnae

narrowly lanceolate, not overlapping, in 1 plane, 3–13 cm;

base oblique, apex acute with subapical and apical teeth same size;

microscales filiform, lacking projections, sparse abaxially, but longer than in other Polystichum species, forming loosely tangled network over blade and sori (such network only in this species), sparse adaxially.

ovate, overlapping, folded inward and twisted horizontally, 0.5–2 cm;

base truncate to oblique, proximal acroscopic pinnules not enlarged;

apex broadly acute;

microscales narrowly lanceolate, with few projections, sparse, ± confined to costa of both surfaces.
Indusia

ciliate.

entire or minutely dentate-erose.
Spores

brown.

dark brown to blackish.
Pinnules

± stalked, linear-falcate to oblique-rhombic, acroscopic auricle well developed on proximal pinnules;

margins spinulose-dentate;

apex acute.

± stalked, rounded, acroscopic auricle not well developed, margins entire to weakly dentate, apex rounded.
2n

= 82.

= 82.

Polystichum dudleyi

Polystichum lemmonii
Habitat Moist forests On rocky serpentine slopes
Elevation 0–100 m (0–300 ft) 1200–2400 m (3900–7900 ft)
Distribution
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; OR; WA; BC
[WildflowerSearch map]
[BONAP county map]
Discussion

Polystichum dudleyi is confined to coastal central California. Hybrids with P. californicum are relatively frequent where these species occur together. These hybrids would key here but, unlike P. dudleyi, they are less divided and have aborted sporangia. The sterile diploid hybrid with P. munitum is also frequent in areas of sympatry. It is indistinguishable from P. californicum except for malformed sporangia and chromosome number (W. H. Wagner Jr. 1973).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Polystichum lemmonii forms sterile hybrids with P. scopulinum and P. munitum. The first hybrid may be abundant where the two parents grow together, which they frequently do in the Wenatchee Mountains of Washington and Siskiyou Mountains of northern California and southwest Oregon. The hybrid is very similar to P. lemmonii but has malformed sporangia and slightly less divided pinnae than P. lemmonii. The P. lemmonii × P. munitum hybrid is morphologically indistinguishable from P. scopulinum; it is a sterile diploid reported only twice from the Wenatchee Mountains of Washington (W. H. Wagner Jr. 1973; P. S. Soltis et al. 1989). It is possible that this hybrid involves P. imbricans and not P. munitum; neither study distinguished between them.

American authors have misapplied the name Polystichum mohrioides (Bory) C. Presl, a South American species, to P. lemmonii.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 2. FNA vol. 2.
Parent taxa Dryopteridaceae > Polystichum Dryopteridaceae > Polystichum
Sibling taxa
P. acrostichoides, P. aleuticum, P. andersonii, P. braunii, P. californicum, P. imbricans, P. kruckebergii, P. kwakiutlii, P. lemmonii, P. lonchitis, P. microchlamys, P. munitum, P. scopulinum, P. setigerum
P. acrostichoides, P. aleuticum, P. andersonii, P. braunii, P. californicum, P. dudleyi, P. imbricans, P. kruckebergii, P. kwakiutlii, P. lonchitis, P. microchlamys, P. munitum, P. scopulinum, P. setigerum
Synonyms P. aculeatum var. dudleyi P. mohrioides var. lemmonii
Name authority Maxon: J. Wash. Acad. Sci. 8: 620. (1918) L. Underwood: Native Ferns ed. 6 116. (1900)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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