Petiole chestnut brown to dark brown, somewhat shiny, glabrous or sometimes viscid-glandular or rarely somewhat white-farinose proximally. Blade thin and herbaceous to thick and leathery, abaxially densely farinose, farina white or yellow, adaxially bright green to yellowish green when fresh, glabrous to glandular or viscid. Pentagramma triangularis occurs in rock crevices and at the base of overhanging boulders in drainages and on slopes and roadbanks. Occasional plants in which the farina is nearly absent may be encountered. These have been described as Pityrogramma triangularis var. viridis Hoover, a name of uncertain application that appears to refer to misshapen-spored hybrids of various parentage within the Pentagramma triangularis complex.

General: Monomorphic leaves, clustered 5-40 cm tall, on short creeping stems, erect or ascending, sometimes branched, scales sharply bicolored, central stripe and tan margins, narrowly lanceolate, margins entire. Leaves: On long chestnut brown to black petiole, rounded, shiny, glabrous; blade triangular pentagonal, 1-2 pinnate below, pinnatifid above, herbaceous to leathery, farinose white to yellow below, bright green to yellowish green glabrous or glandular above; ultimate segments sessile, triangular to lanceolate, margins not recurved to form false indusia. Sporangia: Borne along veins, spores tan to brown, trigonal, coarsely tuberculate. Ecology: Found in rock crevices and at base of boulders in drainages and on slopes from 500-8,500 ft (152-2591 m). Notes: In our region, this species is ssp. maxonii. Paying attention to the way the sporangia is borne along the veins to distinguish this from the similar Bommeria hispida, along with the coarse hairs on the upper surface of B. hispida. Ethnobotany: Chewed for toothache, and taken to mitigate pains after childbirth. Etymology: Pentagramma is thought to come from Greek words for five stripes, while triangularis means having three angles. Sources: FNA 1993