PTERIDACEAE

BRAKE FAMILY

Alan R. Smith and Thomas Lemieux

Perennial, in soil or on or among rocks; rhizome creeping to erect, scaly
Leaves generally all ± alike (or of 2 kinds, fertile and sterile), generally < 50 cm, often < 25 cm; petiole generally thin, wiry, often dark, in transverse section with vascular strands generally 1–3, less often many in a circle; blade generally pinnate or ± palmate-pinnate (see Adiantum ), often 2 or more compound, lower surface often with glands, ± powdery exudate, hairs, or scales; segments round, oblong, fan-shaped, or otherwise, veins generally free
Sporangia in sori or not, marginal, submarginal, or along veins, sometimes covered by recurved, often modified segment margins (false indusia); true indusia 0; spores spheric, sides sometimes flat, scar with 3 radiating branches
Genera in family: ± 40 genera, 500 species: worldwide, especially dry areas. Definition of Cheilanthes and related genera problematic; traditional limits often untenable.

ADIANTUM

Plant in soil or rock crevices; rhizome short-creeping, scales variously colored
Leaf < ± 1 m; petiole cylindric, generally dark reddish brown to blackish, shiny, ± scaly at base; blade 2–3-pinnate or ± palmate-pinnate (1st division ± palmate, subsequent ones pinnate), segments stalked, fan-shaped or oblong, generally lobed, toothed, or both; axes, blades lacking colored exudate
Sporangia borne along veins on and covered by highly modified, recurved part of segment margin, appearing to run together at maturity; false indusia ± semi-circular to linear; spores generally smooth, tan
Species in genus: ± 200 species: tropical, temp
Etymology: (Greek: unwettable)
Widely cultivated.

Native

A. aleuticum (Rupr.) C.A. Paris

FIVE-FINGER FERN

Leaf 20–75(100+) cm; petiole reddish brown to blackish; blade ± palmate-pinnate; segments, cut or lobed generally < 1/2 way to midrib, with often > 4 regular lobes, margins at base converging at 45–90°, stalk color extending gradually into base, midvein generally extending part way along 1 margin
Sporangia: sori (and false indusia) generally 4–6 per segment, generally < 3 mm
Chromosomes: 2n=58
Ecology: Shady, moist banks, streamsides, serpentine
Elevation: < 3400 m.
Bioregional distribution: Northwestern California, Cascade Range, High Sierra Nevada, San Francisco Bay Area, Outer South Coast Ranges, n Channel Islands, Transverse Ranges
Distribution outside California: to Alaska, w Canada, Montana, Colorado, New Mexico; also on serpentine, e US and adjacent Canada
Synonyms: A. pedatum L. var. a. Rupr., var. subpumilum W. Wagner, subsp. calderi Cody; A. boreale C. Presl; A. X tracyi W. Wagner = sterile hybrids with A. jordanii
Horticultural information: IRR or WET, DRN: 4, 5 &SHD: 1, 2, 3, 6, 7, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24.