A N F Keys
1 Lower surface of blades with white or yellowish substance
2 Leaves 1−2-pinnately compound and dissected; blade upper surface glabrous to sparsely hairy, lower surface with yellowish granules secreted from glands evenly distributed along veins, sporangia appearing scattered but occurring along minor veins .. Pentagramma triangularis subsp. triangularis [pics]
2' Leaves typically 3-pinnately compound and dissected; blades surfaces with hairs becoming powderlike (farinose), upper surface sparsely to moderately white-farinose and lower surface densely farinose; margin inrolled forming a false indusium partially concealing sporangia .. Notholaena californica [pics]
1' Lower surface of blades lacking white or yellowish substance
3 Blades and axes conspicuously hairy, and sometimes glandular-hairy or with scales .. Cheilanthes
3' Blades and axes glabrous or essentially so
4 Blades typically > 120 mm long; false indusium concealing many sporangia
5 Ultimate blade segments asymmetrically fan-shaped, broad, thin, and flat, with sporangia borne in lines directly on reflexed lobe margins (false indusia) along outer margins .. Adiantum
5' Ultimate blade segments sclerophyllous with strongly inrolled lateral margins forming false indusia .. Pellaea
4' Blades typically 30−90(−120) mm long, ultimate leaflets feathery and highly dissected, each teeth or lobe forming a false indusium concealing 6−10 sporangia .. Aspidotis californica [pics]
Adiantum L.
MAIDENHAIR, MAIDENHAIR FERN
1 Evergreen perennial growing within waterfalls and creeks where roots always wet; dark color of petiolule extending into leaflet veins; false indusia typically 2−7(−9) per ultimate leaflet, 0.8−1.3 × 1−4.5 mm .. Adiantum capillus-veneris [pics]
1' Drought-deciduous perennial growing in shady southern oak woodland; dark color of petiolule not extending into leaflet veins; false indusia typically 1−3 per ultimate leaflet, 0.4−1.2 × 2−12 mm .. Adiantum jordanii [pics]
1 Leaves typically 3-pinnately compound and conspicuously scaly, with awl-shaped scales along leaf axes and lanceolate to ovate scales on the blades; ultimate leaflet segments strongly inrolled (revolute) forming false indusia .. Cheilanthes covillei [pics]
1' Leaves mostly 2-pinnately compound, lacking scales; ultimate leaflet segments crenate with down-turned margins but neither inrolled nor forming false indusia
2 Shoots densely tomentose .. Cheilanthes newberryi [pics]
2' Shoots glandular-pilose .. Cheilanthes cooperae [pics]
1 Leaves mostly 2-pinnately compound, with petioles straw-colored or tannish to cinnamon or almond brown; principal leaf axes cylindric; ultimate leaflet segments 1.7−13.8 (−15) × 1.4−8 mm, rounded to truncate at tip .. Pellaea andromedifolia [pics]
1' Leaves mostly 3-pinnately compound, with petioles dark brown; principal leaf axes 2-ridged; ultimate leaflet segments 2−6 × 0.5−2 mm, with distinct point at tip .. Pellaea mucronata var. mucronata [pics]
The text of the above keys used with permission from
A Naturalist's Flora of the Santa Monica Mountains and Simi Hills, California
© Copyright
Barry A. Prigge and Arthur C. Gibson
2013