Flora of North America species comparison

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Polystichum lonchitis

Polystichum aleuticum

holly fern, mountain fern, northern holly fern, polystic faux-lonchitis

Aleutian holly fern
Stems

erect to occasionally ascending.

erect.
Leaves

erect, not arching except at tip, 1–6 dm;

bulblets absent.

monomorphic, erect, 1–1.5 dm;

bulblets absent.
Petiole

1/10–1/6 of blade, densely scaly;

scales light brown, gradually diminishing in size distally.

1/6–1/4 length of leaf;

scales tan, sparse or falling off early.
Blade

linear, often widest above middle, 1-pinnate, base narrowed.

linear-lanceolate, 1-pinnate, gradually tapered to base.
Pinnae

oblong to lanceolate to falcate, proximal pinnae ± deltate, rarely overlapping, in 1 plane, 0.5–3 cm, base truncate to oblique, acroscopic auricle well developed;

margins serrulate-spiny with teeth spreading;

apex acute, subapical tooth hardly smaller than apical tooth;

microscales dense, on abaxial surface only.

± deltate to ovate, slightly overlapping, in 1 plane, 4–8 mm;

base truncate, acroscopic auricle well developed;

margins denticulate, not spiny;

apex rounded, not dentate;

microscales linear, lacking projections, dense on both surfaces.
Indusia

entire or minutely dentate-erose.

entire to minutely erose-dentate.
Spores

dark brown.

brown.
2n

= 82.

Polystichum lonchitis

Polystichum aleuticum
Habitat In rock crevices or at base of boulders, mostly in boreal and subalpine coniferous forests or alpine regions Growing in crevices of rocks
Elevation 0–3200 m (0–10500 ft) 0–400 m (0–1300 ft)
Distribution
from FNA
AK; AZ; CA; CO; ID; MI; MN; MT; NV; OR; UT; WA; WI; WY; AB; BC; NF; NS; ON; QC; YT; Greenland
[WildflowerSearch map]
[BONAP county map]
from FNA
AK
[BONAP county map]
Discussion

The hybrid between Polystichum lonchitis and P. acrostichoides (= P. × hagenahii Cody) is discussed under P. acrostichoides. The hybrid with P. braunii (= P. × meyeri Sleep & Reichstein) is discussed under P. braunii. In the Georgian Bay area of Ontario, P. lonchitis hybridizes with Dryopteris goldieana to produce the peculiar × Dryostichum singulare W. H. Wagner (W. H. Wagner Jr., F. S. Wagner et al. 1992).

The spiny spores of P. lonchitis are distinctive and distinguish this from dwarfed forms of other 1-pinnate species.

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

Polystichum aleuticum is known only from Atka and Adak islands, Alaska. Its nearest relatives are in southwest China. Polystichum aleuticum resembles the dwarfed plants of P. kruckebergii, but it differs, especially, in its smaller, more rounded pinna apices and more abundant scales.

Of conservation concern.

(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. dudleyi, P. imbricans, P. kruckebergii, P. kwakiutlii, P. lemmonii, P. microchlamys, P. munitum, P. scopulinum, P. setigerum
P. acrostichoides, P. andersonii, P. braunii, P. californicum, P. dudleyi, P. imbricans, P. kruckebergii, P. kwakiutlii, P. lemmonii, P. lonchitis, P. microchlamys, P. munitum, P. scopulinum, P. setigerum
Synonyms Polypodium lonchitis
Name authority (Linnaeus) Roth: Tent. Fl. Germ. 3(1): 71. (1799) C. Christensen: in Hultén, Svensk Bot. Tidskr. 30: 515, fig. 1a. (1936)
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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