Eastern Bracken Fern

Pteridium aquilinum var. latiusculum

Distinguished from other Pteridium aquilinum varieties by the terminal segments of pinnules 2-4 times longer than wide; segment margins and abaxial surface of blade midrib and costae shaggy.

Petiole 15--100 cm. Blade broadly triangular to sometimes ovate, 3-pinnate or 3-pinnate-pinnatifid at base, 20--80 × 25--50 cm; blade margins and abaxial surface shaggy, rachises and costae glabrous or sparsely pilose abaxially. Pinnae (proximal) broadly triangular, distal pinnae narrowly triangular or oblong; terminal segment of each pinna ca. 2--4 times longer than wide, longer ultimate segments less than their width apart, ca. 3--6 mm wide. Pinnules at 45°--60° angle to costa; fertile ultimate segments adnate or equally decurrent and surcurrent. Outer indusia entire or somewhat erose, glabrous. 2 n = 104.
Ants at nectaries on Bracken Fern Ants (genus uncertain) at nectaries on Bracken Fern. The nectaries (better named as foliar- rather than extra-floral as ferns do not have flowers) are the small dark patches on the leaf stem.

"Bracken extrafloral nectaries secrete sugars and amino acids at low and variable rates. Nectar production increased rapidly to a peak in mid-June, then declined slowly to zero in late August. Seasonal patterns of ant activity on bracken fronds usually mirrored nectar availability." From J. H. Lawton and P. A. Heads (1984). Bracken, Ants and Extrafloral Nectaries. I. the Components of the System in Journal of Animal Ecology 53(3):995.

It has been speculated that the ant-bracken association is one of mutual benefit to both species but various studies over the years have shown that bracken-adapted insects are not seriously affected by the ants and have developed strategies to minimize being killed by the ants. Ants,Bracken Fern,Eastern Bracken Fern,Geotagged,Pteridium aquilinum var. latiusculum,Spring,United States,nectar,nectar eater,nectaries

Naming

Pteridium aquilinum var. latiusculum (Desvaux) L. Underwood ex A. Heller, Cat. N. Amer. Pl. ed. 3. 17. 1909.
Pteris latiuscula Desvaux, Mém. Soc. Linn. Paris 6. 2: 303. 1827
Pteridium latiusculum (Desvaux) Hieronymus ex Fries
Pteridium aquilinum var. latiusculum Pteridium aquilinum var. latiusculum (Bracken Fern) frond uncoiling. One frond in a huge sea of fronds. Eagle fern,Eastern Bracken Fern,Geotagged,Minnesota,Pteridium aquilinum,Pteridium aquilinum var. latiusculum,Spring,United States

Distribution

St. Pierre and Miquelon; Alta., B.C., Man., N.B., Nfld., N.S., P.E.I., Ont., Que.; Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Pa., R.I., S.C., S.Dak., Tenn., Vt., Va., W.Va., Wis.; Mexico in Nuevo León; Europe; Asia.
Pteridium aquilinum var. latiusculum Autumn colors of Pteridium aquilinum var. latiusculum fronds Eastern Bracken Fern,Geotagged,Pteridium aquilinum var. latiusculum,Summer,United States

Status

Because of its aggressive growth bracken fern is considered a weed in many areas.

Behavior

Young fronds have small nectaries positioned near the point where the frond divides. Ants and other insects have been observed feeding on these.

Because this fern often forms large colonies, it provides leafy cover to many kinds of wildlife. The Indigo Bunting and Chestnut-Sided Warbler have been known to construct nests on Bracken Fern.

Habitat

In barrens, pastures, open woodlands in moderately to strong acid soil, abundant, forming large colonies.

Reproduction

By spores and rhizomes.

Predators

Some insects are known to feed on Bracken Fern. They include the caterpillars of some moths: Papaipema pterisii (Bracken Borer Moth), Callopistria cordata (Silver-Spotted Fern Moth), Callopistria granitosa (Granitosa Fern Moth), and Homochlodes fritillaria (Pale Homochlodes). Other insects that feed on this fern include larvae of the sawfly Aneugmenus flavipes, larvae of the sawfly Strongylogaster multicincta, the aphid Macrosiphum ptericolens, and the aphid Mastopoda pteridis.

Defense

The leaves are rarely eaten by mammalian herbivores because of their bitter taste and toxicity. Young leaves produce a cyanide compound when they are damaged. The leaves also contain an enzyme that can cause thiamine deficiency and several carcinogenic compounds that are associated with cancer of the digestive tract and bladder. Both cattle and horses have been seriously poisoned by eating too much Bracken Fern.

References:

Some text fragments are auto parsed from Wikipedia.

http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200003326
https://en.wikipedia.org/wiki/Pteridium_aquilinum
https://www.illinoiswildflowers.info/grasses/plants/bracken_fern.htm
https://gobotany.newenglandwild.org/species/pteridium/aquilinum/
Taxonomy
KingdomPlantae
DivisionPolypodiophyta
ClassPolypodiopsida
OrderPolypodiales
FamilyDennstaedtiaceae
GenusPteridium
SpeciesPteridium aquilinum var. latiusculum