Identifying Southwest Florida's Ferns

Pinnatifid Frond


To identify a fern with a pinnatifid frond, begin with the first question and continue until you get a "yes" answer. If there are additional questions that follow, use the same procedure. Note: pinna (plural: pinnae) is the green leaf-like part of the frond

1. Are the fronds mostly 6" or less in length and growing in clumps? YES, or

1. Do the fronds taper at both ends and is the stem purplish to blackish? YES, or

1. Are the fronds mostly 10" or more in length, with a few to several pairs of pinnae which taper to a point? YES

There are no more pinnatifid frond questions in this section. If it is a pinnatifid frond, the answer to one of the above three questions will be a "yes."

The fronds mostly 10" or more in length, with a few to several pairs of pinnae which taper to a point

2. Is the rhizome thickly covered with golden-brown hairs and finger thick? YES, or

2. Is the rhizome green or black, and very smooth? YES

There are no more pinnatifid frond questions. If it is a pinnatifid frond, the answer to one of the above two questions will be a "yes."

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Pleopeltis polypodioides

(Resurrection Fern, Gray Polypody)

pinnatifid frond

Description
closely packed clumps of open green or curled dry fronds; 4-8" tall; dark green when open; stipe 1/3 to 1/2 frond length; pinnae 7-14 pairs, about 1/8" wide, densely scaly on lower surface but few or no scales on upper surface
Rhizome
long, thin, difficult to detect because of sturdy attachment to host plant
Spores dots, marginal toward tips of lobes (photo right above)
Veins obscure, forking
Growth usually epiphytic on rough tree bark, dead stumps, prostrate rotting logs; occasionally forms terrestrial colonies in well-drained soil; in dry weather, fronds shrivel, shrink, and curl up (photo middle above); turn green and unfurl with rain (resurrect themselves); tips curl inside towards upper surface
Similar

Polypodium ptilodon (Comb Polypody)

  • much larger (frond 20-36")
  • terrestrial
  • blade tapers toward both tip and base while Resurrection Fern only tapers at tip

Pecluma ptilodon

(Comb Polypody, Greater Comb)

pinnatifid frond

Description
deeply pinnatifid to the extent it almost appears to be pinnate; blade tapers at both ends; stipe (stem) purplish to blackish (middle photo); fronds to 3' long; when dries out, pinna tend to curl inward (right photo)
Rhizome
short creeping
Spores oval, in rows between midveins and margins of blade segments
Veins forked
Growth terrestrial or growing on cypress knees and old stumps in moist woods and hammocks
Similar

Pleopeltis polypodioides (Resurrection Fern)

  • much smaller (fronds to 8" or less)
  • Resurrection Fern blade only tapers at tip

Phlebodium aureum

(Golden Polypody, Cabbage Palm Fern, Serpent Fern, Rabbit's Foot Fern, Golden Serpent Fern)

pinnatifid frond

Description
frond scattered along the rootstock; light green to yellowish-green; spreading; widely lobed; 15-30" tall; stipe 1/2 frond length
Rhizome
stout, creeping, serpent-like, finger-thick and densely covered with long golden-brown to reddish-brown hairs (photo middle above)
Spores sori in one or two rows on each side of the pinna midvein (photo right above)
Veins netted with two veins feeding each sorus
Growth epiphytic; droops from old palm frond boots or other stable, nutrient-rich nooks and crannies, especially cypress bases; rarely terrestrial
Similar

Pecluma ptilodon (Comb Polypody)

  • mostly terrestrial
  • blade tapers toward both tip and base while Golden Polypody only tapers at tip

Phymatodes scolopendria scolopendria (Wart Fern)

  • rhizome not hairy
  • tips of pinae sharply pointed

Phymatodes scolopendria (exotic)

(Wart Fern, Serpent Fern)

pinnatifid frond

NOTE: a cultivated species from the Old World tropics frequently used by landscapers around buildings; has escaped into the wild

Description
green fronds scattered along the rootstock; light green to yellowish-green; thick, spreading; widely lobed; 15-30" tall; stipe 1/2 frond length; pinnae come to sharp point
Rhizome
thin, smooth, usually purplish to blackish
Spores sori in one or two rows on each side of the pinna midvein
Veins netted with two veins feeding each sorus
Growth mostly terrestrial but can be epiphytic
Similar

Pecluma ptilodon (Comb Polypody)

  • mostly terrestrial
  • blade tapers toward both tip and base while Wart Fern only tapers at tip

Phlebodium aureum (Golden Polypody)

  • rhizome thickly covered with golden to reddish-brown "hairs"
  • tips of pinae come to point, but not as sharp
  • fronds usually lighter green in color