NOTABLE FERN FAMILIES
Reading edition
OSMUNDA (Flowering Ferns)
Tall swamp ferns, growing in large crowns, with the fertile fronds or portions conspicuously unlike the sterile; sporangia opening by a longitudinal cleft into two valves.
ONOCLEA
Coarse ferns, with the fertile fronds rolled up into necklace-like or berry-like segments, and entirely unlike the broad, pinnatifid sterile ones. Fertile fronds unrolling at maturity, allowing the spores to escape, and remaining long after the sterile fronds have perished; sporangia stalked, ringed, bursting transversely.
WOODSIA
Small or medium-sized ferns, growing among rocks, with 1-2 pinnate or pinnatifid fronds and round fruit-dots; indusium thin and often evanescent, attached by its base under the sporangia, either small and open, or else early bursting at the top into irregular pieces or lobes; sporangia stalked, ringed, bursting transversely.
CYSTOPTERIS (Bladder Ferns)
Delicate rock or wood ferns, with 2-3 pinnate fronds and round fruit-dots; indusium hood-like, attached by a broad base to the inner side, soon thrown back or withering away; sporangia as above.
ASPIDIUM (Shield Ferns)
Ferns with 1-3 pinnate fronds and round fruit-dots; indusium more or less flat, fixed by its depressed centre; sporangia as above.
PHEGOPTERIS (Beech Ferns)
Medium-sized or small ferns, with 2-3 pinnatifid or ternate leaves, and small, round, uncovered fruit-dots; sporangia as above.
WOODWARDIA (Chain Ferns)
Large and rather coarse ferns of swamps or wet woods, fronds pinnate or nearly twice-pinnate; fruit-dots oblong or linear, sunk in cavities of the leaf and arranged in chain-like rows; indusium lid-like, somewhat leathery, fixed by its outer margin to a veinlet; veins more or less reticulated; sporangia as above.
ASPLENIUM (Spleenworts)
Large or small ferns, with varying fronds and linear or oblong fruit-dots; indusium straight or curved; sporangia as above.
PELLÆA (Cliff Brakes)
Small or medium-sized rock ferns, with pinnate fronds and sporangia borne beneath the reflexed margins of the pinnæ; sporangia as above.
BOTRYCHIUM (Moonworts)
(Belonging to the Fern Allies)
Fleshy plants, with fronds (usually solitary) divided into a sterile and a fertile portion, the bud for the succeeding year embedded in the base of the stem.