Adiantum pedatum

Another entry written by Taisha today:

Today’s image of Adiantum pedatum was taken by swampr0se@Flickr on May 22, 2011. Ferns from this genus are among my favourites. I am drawn to the aesthetic contrast between the dark-coloured stipe and rachis to the bright green and glossy pinnules. Thanks swampr0se for the photo!

Adiantum pedatum of the Pteridaceae is one of about two hundred species in the genus Adiantum. Members of this genus are known for their glossy fronds that shed water readily and their gleaming blackish-brown stipes. Uniquely, this genus bears sporangia on the abaxial margins of the pinnules covered by a false indusium (formed by inrolling of the margins), rather than on the margin of the lamina like many other ferns. The arching fronds grow from creeping rhizomes that spread and form colonies over time. The fan-shaped blade is segmented into rounded lobes separated by shallow sinuses. This species sporulates from summer through autumn.

The northern maidenhair fern is found growing on humus-covered slopes and moist lime soils across eastern North America, however there are disjunct populations in China and other parts of eastern Asia. Adiantum pedatum is a part of the Adiantum pedatum complex comprising of three other species, Adiantum aleuticum, Adiantum myriosorum and Adiantum viridimontanum. Those species belonging to the Adiantum pedatum complex are characterised by pedately-divided frond clusters growing from clump-forming rhizomes. In a study looking at the biogeographic disjunction of the Adiantum pedatum complex between eastern Asia and North America by Lu et al., it was suggested that the Adiantum pedatum complex is of Asian origin dating to 4.27 million years ago (Ma) in the Pliocene. Migration to North America seems to have occurred in the late Pliocene to early Pleistocene via the Bering land bridge. Lu et al. also propose that the clades within North America, Adiantum pedatum and Adiantum aleuticum, dispersed back to eastern Asia about 0.8Ma, likely by way of the Aleutian Islands south of the Bering sea. (see: Lu J-M. et al. 2011. Biogeographic disjuction between eastern Asia and North America in the Adiantum pedatum complex (Pteridaceae). American Journal of Botany. 98(10):1680-1693.).

Adiantum pedatum

7 responses to “Adiantum pedatum”

  1. Niña Klinck

    This is one of my favorite plants in the world. I love it’s outrageous green in the spring and the colonies that can sometimes cover whole banks in the sugar woods. The fronds catch every small breeze and gently move in a very different motion than all the other ferns. Sigh.

  2. michael aman

    One of my favorites, too. So glad it migrated to North America! When I have had to move, I’ve taken divisions of my favorite plants with me to the new garden. One move was so sudden that I had to make an impulse decision. I only had time to dig one plant and that was my maidenhair fern.

  3. Mary Yee

    Exquisite photo, thank you. I had no idea the genus was so large!

  4. Jessica

    One of my absolute all-time favorite plants, too. And what a beautiful photo.
    Seems like there’s something about this plant that really touches people’s hearts.
    Thanks so much for all the info and great photo.

  5. Denis Dooley

    I’d thought that the west coast version of the Maidenhair Fern was split off and christened A. aleuticum. Was this lumped back in, or is the Western Maidenhair Fern still a separate species?

  6. Sara

    Oh I am so excited to see this one. I have two growing as potted plants in my house. I found them nearly dead at a Home Depot and have nursed them back to health. The staff there had no idea what kind of plant it was and I also had never seen one. So now I know!! Thanks so much for the pictures and good description of the sporangia. Mine has just started doing this.

  7. Sue Frisch

    Lovely photo of the structure…the chambered nautilus of the plant world?

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