Robert W. Freckmann Herbarium

Taxonomy of Vascular Plants


Plants of Wisconsin

Vascular Plants

[Click on species name to see its detail page]

Glossary drawings

Key to the Dryopteris Genus in Wisconsin 

by Lauren Ebbecke

Dryopteris Descriptions

26a.  Blades of fronds small (10-30 cm long), very scaly on the undersurface and gradually tapered downward with short stipe less than 6 cm wide; rachis, veins, and margin glandular; habitat includes cliffs, usually basalt and granite, and prairies; a noteworthy characteristic is the persistence of old brown curled fronds hanging in masses below the plant; this plant also has a distinct fragrance its name……Dryopteris fragrans

26b.  Blades of fronds large (more than 25 cm long), scales few or absent (scales may be abundant on stipe)………..27 

27a. Blades bipinnate, or less divided…….28 

28a. Sori borne near the margin of leaf segments; blades evergreen and blue-green in color with fronds approximately 5-16 cm long….…         D. marginalis 

28b. Sori not marginal; blades are 5-20 cm long and conspicuously narrowed at the base; stipe is less than length of the frond, and bears 2 distinct types of scales, one broad and the other extremely narrow and hair-like; habitat includes northern upland forests and it is identified as a “special concern” as it has only been reported in 3 counties.............D. filix-max 

29a.  lowest pinnae ovate (broadest above the base); sori near midveins  of lobes; petiole is about 1/3 of the length of the frond and is conspicuously scaly, the broad scales dark colored with a lighter border; easily identified by the broad ovate blade, with its abruptly tapering tip; habitat includes scattered locations throughout the state and is generally uncommon.…….D. goldiana 

29b.  lowest pinnae triangular (broadest at base); scales at base of stipe tan; habitats include swamps and wet meadows…….30 

30a.  Pinnae 8-14 cm long; basal pinnae 1 - 2 times longer than wide and much smaller than those above; fronds slightly reduced downward, sterile fronds are evergreen while fertile fronds die in the winter; habitat includes swamps in southern Wisconsin and it is considered rare…………………D. clintoniana

30b.  pinnae 4-8 cm long; basal pinnae about as wide as long and nearly uniform in width except where narrowed to the tip; fronds distinctly reduced downward; sterile fronds are evergreen while fertile fronds die in the winter; habitat includes swamps and wet meadows; more common in the north………………….D. cristata 

27b. Blade bipinnate-pinnatifid or tripinnate……..31 

31a. Lower, basal pinnule of lowest pinna shorter than adjacent pinnule; surface of blade with glands on indusia and midrib; evergreen fronds approximately 30 – 90 cm ……….. D. intermedia

31b. Lower basal pinnule of lowest pinna longer than adjacent pinnules; surface of blade without glands……..32 

32a. Lower basal pinnule of lowest pinna more than twice as long as upper basal pinnule of lowest pinna; blade is large, tripinnate and very triangular; fronds are the first to become senescent in Wisconsin; habitat includes cool moist slopes and rocky slopes in northern counties and state islands. …………D. expansa 

32b. Lower basal pinnule of lowest pinna less than twice as long as upper basal pinnule of lowest pinna;  has approximately 14” – 28” fronds and blades are longer than wide, 2 pinnate-pinnatifid and tan scales are conspicuous at the base of the stipe; variety of habitats statewide ……….……………D. carthusiana

(return to original number 30)


Ferns (Polypodiophyta), Glossary drawings, Page 1, 2, 3a4, 5, 6

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