Specimen record
Christmas Fern
Polystichum acrostichoides
Description
The most common evergreen fern of New England forests, Christmas fern stays green through winter, lying flat against the forest floor under the snow. The common name comes from its use in holiday decorations and the fact that each pinna (leaflet) is shaped like a Christmas stocking, with a small lobe (the 'toe') at the base. Fertile pinnae at the frond tip are distinctly smaller and bear brown sori on their undersides.
Identification tips
- 1Evergreen — green fronds visible even in winter, lying flat on the forest floor
- 2Each pinna has a small 'ear' or lobe at the base on the upper side (looks like a stocking toe)
- 3Leathery, glossy dark green once-pinnate fronds in a vase-shaped cluster
- 4Fertile pinnae near the frond tip are noticeably smaller and bear round brown sori underneath
- 5Fiddleheads in spring covered with conspicuous silvery-white scales
Specimen & preservation notes
Press a full frond — they are the right size for standard herbarium paper. Include a fertile frond showing the smaller upper pinnae with sori. Evergreen fronds collected in winter show the persistent character. These are abundant — excellent for student practice pressing.
Habitats
Collection calendar
| Wk | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov |
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Collection notes
Season check
No flowering records for this species yet.
Flowering records: 0 iNaturalist observations, Massachusetts · Nearby: 344 observations within 25 km