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.

NOTHOLAENA

Plant in soil or often in granite rock crevices; rhizome short-creeping to suberect, scales linear-lanceolate
Leaf: petiole generally cylindric, dark brown to black, glabrous to ± scaly; blade 2–4-pinnate, axes and segments with white to yellow ± powdery exudate on lower, often upper sides, segments generally sessile, sometimes slightly narrower at base
Sporangia in ± continuous, marginal bands at maturity; segment margin recurved and partly covering sporangia, unmodified; spores finely ridged or granular, often blackish
Species in genus: ± 25 species: generally Mex, sw US, few in Caribbean, South America
Etymology: (Greek: false cloak, from leaf blade margin not reflexed as it is in Cheilanthes )
Reference: [Tryon 1956 Contr Gray Herb 179:1–106]