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    The Ferns and Fern Allies of Jefferson County, Kentucky

    Jefferson County, Kentucky, is in north-central Kentucky, on the western side of the Cincinnati Arch, an anticlinal geologic structure that extends from Indiana and Ohio through Kentucky and Tennessee. The eastern two-thirds of the county is in the Bluegrass area of central Kentucky, comprising Ordovician and Devonian limestones, dolomites and shales, with the limestone predominating. The northwest, far west, and southwest extremes of the county are river plains and terraces bordering the Ohio River. An area in the west-central county is a slack-water flat, a remnant of a large glacial lake, and which was a large swamp prior to settlement of the area by the Europeans. The western half of the extreme southern area of the county is in the Knobs, a geological escarpment representing the transition from the higher and younger Pennyrile to the west and south, to the lower and older Bluegrass to the east. The Knobs comprise principally siltstone and shale, and include the area of the Jefferson County Memorial Forest.

    Kingdom: Plantae

    Divison: Lycopodiophyta

    Class: Lycopodiopsida

    Order: Lycopodiales
    Family: Lycopodiaceae: the clubmosses

    Genus: Diphasiastrum
    Diphasiatrum digitatum: ground-cedar or running-cedar
    Frequent throughout the county in old fields and young woods, often forming extensive colonies, especially in redcedar groves in the Bluegrass area.

    Order: Selaginellales
    Family: Selaginellaceae: the spikemosses

    Genus: Selaginella
    Selaginella apoda: meadow spikemoss
    Rare, in open, grassy, moist bottoms where the overgrowth is not tall. Known in the county only from the Knobs, in the County Forest Area. Particularly to be seen at Tom Wallace Recreation Area. Easily overlooked.

    Division: Polypodiophyta

    Class: Equisetopsida: the horsetails and scouring-rushes

    Order: Equisetales
    Family: Equisetaceae: the horsetails and scouring-rushes

    Genus: Equisetum
    Equisetum arvense: the field horsetail or shavegrass
    Occasional in moist, open fields and other areas, especially in stream bottoms.
    Equisetum hyemale var. affine: scouring-rush
    Frequent in the western river flats of the county, especially in sandy soil.

    Class: Ophioglossopsida

    Order: Ophioglossales
    Family: Ophioglossaceae: the adders-tongues

    Genus: Ophioglossum
    Ophioglossum pycnostichum: adders-tongue
    Usually dying down by early to mid-summer, occasional in bottomland thickets and easily overlooked.
    Order: Botrychiales Family: Botrychiaceae: the grape-ferns
    Genus: Sceptridium
    Sceptridium dissectum (aka B. obliquum): oblique grape-fern
    Frequent, in young woodlands, found in the County Forest as well; often associated with Diphasium digitatum.
    Genus: Botrypus
    Botrypus virginianum: rattlesnake fern
    Common, found in rich soils, especially woodland borders; found in the County Forest.

    Class: Polypodiopsida

    Order: Osmundales
    Family: Osmundaceae: the flowering ferns
    Genus: Osmunda
    Osmunda claytoniana: interrupted fern
    Occasional in the County Forest area only, favoring moist hillside pockets in the forest.
    Order: Pteridales
    Family: Adiantaceae: the maidenhair ferns
    Genus: Adiantum
    Adiantum pedatum: maidenhair fern
    Frequent throughout the county, including in the County Forest; in moist, wooded valley bottoms and sometimes on moist limestone faces.
    Family: Cheilanthaeaceae
    Genus: Pellaea
    Pellaea atropurpurea: purple-stemmed cliffbrake
    Occasional on limestone outcroppings in the eastern county; a hybrid offspring with P. glabella as one parent, not sexually fertile but reproducing by apogamous spore
    Pellaea glabella: smooth cliffbrake
    Occasional on limestone outcroppings in the eastern county, in more exposed locations than P. atropurpurea; one of the parents of the hybrid P. atropurpurea
    Order: Hypolepidales
    Family: Hypolepidaceae
    Genus: Pteridium
    Pteridium aquilinum: bracken
    Probably the most common fern in the world, but only occasional in Jefferson County, including the County Forest; growing in open fields and open woods situations
    Order: Aspleniales
    Family: Aspleniaceae: the spleenworts
    Genus: Asplenium
    Asplenium platyneuron: ebony spleenwort
    Common, growing throughout the county in a wide variety of situations, including the County Forest; especially found in old fields but including rock and stonework.
    Asplenium rhizophyllum (aka Camptosorus rhizophyllus): walking fern
    Common, found on densely mossy rock, often forming extensive colonies on mossy limestone, often to be seen in the small stream gorges of the eastern county; once collected from the County Forest but not now known there.
    Asplenium ruta-muraria: wall-rue
    Rare, found in crevices on hard, well-weathered limestone in somewhat dry locations.
    Family: Woodsiaceae
    Genus: Athyrium
    Athyrium asplenioides: southern lady fern
    Frequent throughout the county, including the County Forest; favoring wet bottoms.
    Diplazium pycnocarpon (aka Athyrium pycnocarpon): narrow glade fern
    Common throughout the county, especially in the County Forest, often forming extensive colonies; favoring open, moist hillsides.
    Deparia thelypterioides (aka Athyrium thelypterioides): silvery glade fern
    Frequent throughout the county, especially in the County Forest; favoring moist slopes and streambanks.
    Genus: Cystopteris
    Cystopteris bulbifera: bulblet fern
    Common in the eastern county, growing in moist crevices in limestone.
    Cystopteris protrusa: lowland fragile fern
    Common throughout the county, including the County Forest, often forming extensive colonies on moist hillsides and stream bottoms, usually disappearing by middle to late summer.
    Genus: Woodsia
    Woodsia obtusa: blunt-lobed cliff fern
    Frequent throughout the county, including the County Forest; usually growing in crevices of dry to moist rock in the eastern county, usually growing in scree high on slopes in the County Forest.
    Family: Onocleaceae: the bead-ferns
    Genus: Onoclea
    Onoclea sensibilis: sensitive fern
    Common throughout the county, especially the central slack-water flats but including the County Forest; probably the commonest fern in the county; favoring open, sunny, wet areas.
    Family: Thelypteridaceae: the female ferns
    Genus: Thelypteris
    Thelypteris noveboracensis: New-York fern
    Frequent throughout the county, especially in the County Forest; growing in moist stream bottoms in woodlands.
    Genus: Phegopteris
    Phegopteris hexagonoptera: broad beech fern
    Common throughout the county, including the County Forest; growing in a variety of woodlands.
    Order: Dryopteridales
    Dryopteridaceae: the wood ferns
    Genus: Dryopteris
    Dryopteris carthusiana (aka D. spinulosa): spinulose wood fern
    Rare in the county, currently known from only one hillside location in the County Forest.
    Dryopteris goldiana: Goldie's wood fern
    Rare in the county, currently known from one colony in the County Forest; found in moist stream bottoms in rich soil.
    Genus: Polystichum
    Polystichum acrostichoides: Christmas fern
    Common throughout the county, including the County Forest; found in a wide variety of situations, but particularly near the bottoms of steep, wooded slopes.

    Other Ferns and Fern-Allies Once Collected in Jefferson County, But Not Now Known to Exist:

    Lycopodiaceae: the clubmoss family
    Huperzia lucidula (aka Lycopodium lucidulum): shining clubmoss
    Known from one old collection near the intersection of South Park Road and I-65; favoring moist, acid seeps.
    Osmundaceae: the royal fern family
    Osmundastrum cinnamomeum: cinnamon fern
    Formerly common in acid, swampy areas of the county; no longer known to exist in the county.
    Osmunda regalis: royal fern
    Once very common in the central swamps and wetwoods of Jefferson County; no longer known in the county.
    Polypodiaceae: the polypody family
    Polypodium polypodioides: resurrection fern
    Known from a few places on limestone rock in the eastern county; usually growing on semi-exposed limestone in this area but also occasionally on trees; likely still to be found in the county.
    Polypodium virginianum: the Virginia rock-cap fern
    Known from one old collection along Bearcamp Road in the County Forest area; favoring the tops of sandstone rock shelves.
    Dennstaedtiaceae: the dennstaedtioid fern family
    Dennstaedtia punctilobula: hay-scented fern
    Known from one old collection near Penile Road in the County Forest area; favoring moist open fields.
    Aspleniaceae: the spleenwort family
    Asplenium pinnatifidum: pinnatifid spleenwort
    Known from one old collection in the County Forest area; favoring pockets in weathered sandstone.
    Asplenium trichomanes: maidenhair spleenwort
    Known from one old collection on Holsclaw Hill in the County Forest; favoring crevices in well-weathered limestone or sandstone.
    Dryopteridaceae (aka Aspidiaceae): the dryopteroid fern family
    Dryopteris intermedia: intermediate wood fern
    Known from one old collection near Bearcamp Road in the County Forest area; favoring moist, acid rock in shaded locations.
    Dryopteris marginalis: marginal wood fern
    Known from one old collection near Bearcamp Road in the County Forest area; favoring moist, acid rock in shaded locations.
    Blechnaceae: the chain fern family
    Lorinseria areolata: net-vein chain fern
    Never collected but one plant was found in wet woods off McCauley Lane in the Okolona area; however, it died in the summer drought in 1988. Probably once more widespread, although never collected.



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    This page was last revised on May 14, 2008.