Dennstaedtiaceae, Polypodiaceae, and Pteridaceae

Fern Family

Venus Maidenhair Fern

FAMILY: Fern family (Pteridaceae) – Adiantum genus. This genus has formerly been placed in the Polypodiaceae.

SPECIES: Venus or common maidenhair fern (Adiantum capillus-veneris L.).

TO UTILIZE AS FOOD: (tea and flavoring only): Aboveground parts can be steeped into tea or boiled down into syrup. In the past, Venus maidenhair ferns were valued for making tea and flavoring desserts, but they were never utilized as food. Tea made from the aboveground parts is refreshing, yet poorly defined. Elements unique to ferns merge with grass-like and hay-like accents. It’s a mild tea. Sweetness is barely perceptible. Concentrating the tea by boiling away the water highlights a subtle pleasantness. Venus maidenhair tea derives its appeal from a lack of harsh characteristics rather than an abundance of intriguing ones. Venus maidenhair ferns are uncommon in the Southwest and hardly worth sacrificing when so many better choices for making tea are available.

IDENTIFICATION: Only 2 species of the Adiantum genus are found in the Southwest, of which only Venus maidenhair fern (A. capillus-veneris) is likely to be encountered. The black stalks and fan-shaped leaflets are very distinctive. Instead of flowers, ferns have tiny structures called sori (usually on the leaf margins) that produce spores rather than seeds. Sori are clusters of smaller structures called sporangia, in the same sense that flower clusters consist of many individual flowers.

Description of Venus maidenhair fern (Adiantum capillus-veneris): FORM delicate fern up to about 35 cm tall, spreading by rhizomes; LEAVES (fronds) compound; fertile and vegetative fronds appearing similar; stalks (stipes) blackish, with the dark coloring often extending into the leaflets; blades once or twice pinnate; ultimate leaflets fan-shaped, about as long as wide; margins rolled under and protecting the sori; FLOWERS absent; SORI borne underneath the leaflets along the margins; indusia (protective coverings) absent; FRUITS absent; seeds absent; HABITAT rocky canyon seeps; across the southern United States; producing spores in spring or summer.

REFERENCES: Venus maidenhair fern (Adiantum capillus-veneris): aerial parts (as tea) Couplan (p. 19).

Western Polypod Fern

FAMILY: Fern family (Polypodiaceae) – Polypodium genus.

SPECIES: Western polypod fern (Polypodium hesperium Maxon).

TO UTILIZE AS FOOD: The rhizomes of western polypod fern can be chewed. Acrid saponins and bitter resins are reported to overwhelm the scanty licorice-like sweetness. A related species of the Pacific states called licorice fern (P. glycyrrhiza) can be utilized in the same way (Couplan p. 21). Neither of these species were located during the fieldwork conducted for this reference.

IDENTIFICATION: The Polypodium genus is represented by about 10 species in the continental United States, of which only 1 occurs in the Southwest. Ferns produce spores rather than seeds. Spores are produced in structures called sporangia rather than flowers, and sporangia are often grouped into clusters called sori appearing underneath the leaves. Sori are often covered by indusia, but these coverings are absent in the Polypodium genus.

Description of western polypod fern (Polypodium hesperium): FORM evergreen fern; ROOTS (rhizomes) long, brown, scaly, 3-6 mm in diameter, and occasionally with white waxy coatings; LEAVES (fronds) simple; scattered singly along the rhizomes; stalks up to 20 cm long, hairless, and with the upper surfaces 2-grooved; blades up to 25 cm long, and deeply pinnately cut into alternating segments; venation free (the veins not reaching the margins); FLOWERS absent; SORI (clusters of reproductive structures) dot-like, ovate, and about 1-3 mm in diameter; borne at the tips of veins; each with 1-7, dark reddish-brown, glandular, sac-like structures (sporangia) producing spores; indusia absent; FRUITS absent; HABITAT shaded canyons, preferring to grow on rocks; rare in the Southwest; producing spores in summer and autumn.

REFERENCES: Western polypod fern (Polypodium hesperium): rhizomes Moerman (p. 190).

Bracken Fern

FAMILY: Fern family (Dennstaedtiaceae) – Pteridium genus. This genus has formerly been placed in the Polypodiaceae.

SPECIES: Bracken fern, western bracken fern, or brake (Pteridium aquilinum (L.) Khun).

TO UTILIZE AS FOOD: Warning! Bracken fern contains a variety of toxins including thiaminase, ptaquiloside, and prunasin. Thiaminase is an enzyme that causes a vitamin deficiency disease called beriberi, marked by a severe loss of energy. Ptaquiloside is an “illudane-type sesquiterpene glucoside” (if that helps anyone) that can damage DNA, damage bone marrow, and cause various types of cancer. Prunasin is a cyanide-containing glucoside. Fortunately, these compounds can be eliminated, or at least greatly reduced, by boiling the various parts in water (Acamovic p. 232, Brimer pp. 116-118, Deshpande p. 372, or D’Mello 2003 pp. 17-18). Other harmful compounds may endure the process. Ptaquiloside is most concentrated in the young fronds (commonly called fiddleheads), which is the part most often cited as edible. For this reason, the young fronds or any other parts of bracken fern should never be consumed raw.

Young fronds (fiddleheads) of bracken fern are a well known wild food appearing from mid to late spring, or in summer in more northern latitudes. For reasons noted above, this wild food must be cooked. Boiled, steamed, or sautéed bracken fronds are delicious and the texture is pleasant. No bitter, acrid, stringy, chewy, or slimy characteristics are present to ruin the experience. Young fronds are covered with silver-brown hairs that readily detach after boiling. Tips of the fronds are especially good. Limiting consumption of this wild food would be wise.

Rhizomes of bracken fern are black with tough white cores. Only the growing ends are tender. Raw rhizomes are toxic. They must be cooked. After long hours of cooking, they were consumed by indigenous people throughout most of the world, often as a principal food source (Couplan pp. 21-23). Based on the rhizomes I sampled, the flavor is somewhat like licorice tainted with a dreadful medicine, and the odd aroma suggests that they are inedible. Despite their historical importance, bracken fern rhizomes should always be regarded with caution. Most wild foods taste like food, but a few don’t. The flavor of bracken fern rhizomes has starchy overtones reminiscent of food, but the overall flavor does not suggest a food source that would be safe to eat. Starch can be obtained by cooking the rhizomes and chewing the softer portions off the wiry cores. It can also be obtained by grinding the rhizomes into flour and sifting out the debris. Gathering the rhizomes is reasonably easy. They can be gathered anytime, even in winter if they can be found and the ground is soft enough to dig—which it often is because bracken ferns prefer sandy soil. Almost any evergreen forest has a supply of bracken ferns. In the southwestern United States, they’re associated with oak, aspen, pine, fir, spruce, and other floristic communities of the mountains. They’re often a dominant part of the understory. Overall, caution is advised when consuming any parts of bracken ferns.

IDENTIFICATION: Bracken fern is one of the most successful ferns on Earth. It’s abundant on all continents except Antarctica, including mountainous regions of southwestern North America. Currently, it has 3-10 varieties, of which only the pubescens variety is found in the Southwest. Sometimes these varieties are recognized as species.

Description of bracken fern (Pteridium aquilinum): FORM fern about 5-13 dm tall; ROOTS (rhizomes) long, black, hairy, 10-15 mm thick, lacking scales, and spreading extensively; LEAVES (fronds) compound; scattered along the rhizomes; stalks (stipes) green; blades bi- or tri-pinnate and triangular in outline; ultimate segments linear-oblong or lobed; margins rolled; lower surfaces densely hairy; emerging fronds (fiddleheads) coiled, claw-like, and covered with silvery-brown hairs; FLOWERS absent; SORI borne along the leaf margins; appearing as a nearly continuous thickening of the margins; indusia thin; HABITAT oak, pine, and aspen woodlands; throughout the United States; appearing early in the season and often growing in vast colonies.

REFERENCES: Western bracken fern (Pteridium aquilinum): rhizomes Couplan (pp. 21-23) and Moerman (pp. 203-204); young fronds Brill (pp. 31-32), Couplan (pp. 21-23) and Moerman (pp. 203-204).