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| California polypody (Polypodium californicum) - leafing out in Mother Nature's Garden of Health |
My,
how it’s rained recently; almost 9 inches in January alone. That’s as much as we sometimes get in an
entire year! The ground is really moist,
and some of our perennials are looking the best they have in years. Coming into its own right now is the one
native fern we currently grow – the California polypody, Polypodium californicum. The
scientific name is pronounced pol-ee-PODE-ee-um ka-li-FOR-ni-kum.
California
polypody is a member of the Polypody fern family (Polypodiaceae), a large family of ferns with about 40-50 genera and
500-700 species worldwide. At one time, many more ferns were included in the
family and the exact numbers are still debated. Most polypodies grow in moist climates,
commonly in rainforests. The majority
are also epiphytes (plants that grow on other plants, rather than in the
soil). That makes California polypody
unique on two accounts: it grows in a mediterranean climate and it grows in the ground.
Ferns
are placed in a separate division of the Plant Kingdom (Pteridophyta).
Pteridophytes are ancient plant forms that do not produce seeds. Their life cycle involves alternating
generations of sporophytes (what we commonly think of as the ‘ferns’) and gametophytes
(small, moss-like plants). Reproduction depends
on water; sperm can only reach eggs to fertilize them via water.
Sporophytes
produce tiny spores in small, rounded sori
on the bottom surfaces of the leaves.
The spores, given moist growing conditions, develop into the gametophye
generation, which produces eggs and sperm.
Fertilized eggs, when they occur, then give rise to new sporophyte
plants. For more on ferns and their reproduction see references 1 and 2, below.
California
has five native Polypodies. [3] Only
two are native to Southern California: California polypody and Western polypody
(Polypodium hesperium). California polypody has a natural range from
the Northern California coast to the coast of Baja California, Mexico. It grows in shaded canyons, along streambanks,
on rocky, north-facing slopes, in rock crevices and on cliffs/coastal bluffs.
It can still be found in the coastal sage scrub and chaparral communities of
the Santa Monica and San Gabriel Mountain foothills and on the southern Channel
Islands, at elevations below about 4000 ft. (1500 m.).
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| California polypody (Polypodium californicum) - frond (leaf) |
California polypody is a small, herbaceous perennial
fern. Its sporophyte generation grows
1-2 ft tall (usually 6-12 inches, but may be taller in garden) and about as
wide. Like most ferns, its leaves (called
fronds) are compound, with many
leaflets (called pinnae in the ferns)
along a stout, hairy midrib. The fronds
are fairly simple, being only once pinnate.
The pinnae have rounded tips and are minutely serrate. The sori develop on the underside of the
pinnae; the indentations of the sori can be seen from the upper side in young
leaves (see above).
Plants spread slowly via stout underground stems
(rhizomes). The rhizomes have many knobby projections, alluded to by the
scientific name (poly = many; pody = feet). Plants die back to the ground in
the dry season (summer/fall). New fronds
appear with the winter rains.
California polypody is a nice fern for the
garden. Its small size makes it
appropriate for even small spaces. While
preferring a well-drained soil, Polypodium californicum can be grown in most S. California
soils. It will tolerate morning sun,
dappled shade or quite shady conditions.
It likes good winter/spring moisture, but then needs to dry out by late
summer/early fall. You can water it once
a month or so in early/mid-summer and plants are fine with winter flooding.
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| California polypody (Polypodium californicum) - in shady garden with sedges, Mugwort (Artemisia douglasiana) |
Ferns
don’t ask for much in the way of management.
Trim off dead fronds for neatness – that’s about it. You
can grow Polypodium californicum just
about anywhere with some shade and late summer dry. This is a cute one for a porch
container. It’s charming with shade-tolerant
Carex, Heucheras, Columbine (Acquilegia)
and other perennials with similar requirements. It’s often used in moist rock gardens, rocky
slopes and fern grottos. But it can even
do well in the dense shade under native oaks and other trees.
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| 'Sarah Lyman' polypody (Polypodium 'Sarah Lyman') - leaves are quite showy |
A
fern often sold as Polypodium
californicum ‘Sarah Lyman’ or Polypodium calirhiza 'Sarah Lyman' is actually a hybrid
between Polypodium californicum and P. hesperium. This cultivar has all the characteristics of
California polypody, but its leaves are ruffled and much showier. It’s a little charmer that’s widely available
from California native nurseries and online fern sources. We’ve grown it and love it!
The
young fronds (fiddlenecks) can be eaten, raw or cooked, fresh or dried. Native Californians used the roots in the
treatment of coughs, chest soreness, and the pains of rheumatism. Plants were also used as a laxative and for
skin wounds. This is not a major
medicinal plant, but was useful enough to include in our Garden of Health.
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| California polypody (Polypodium californicum) - S. California native fern |
Native ferns are an interesting addition to local
gardens. While not as important food,
habitat or medicinal plants as other natives, they add a particular charm and
personality to the shady garden. We love the idea of creating a Victorian fern
grotto using California natives – perhaps we’ll do so sometime. As perennials, Polypodies die back each year,
but then reappear with the rains as if by magic. It’s such a joy to see the new fronds unfurl
each season. Are you hooked yet?
For more
pictures of this plant see: http://www.slideshare.net/cvadheim/polypodium-californicum-web-show
For plant
information sheets on other native plants see: http://nativeplantscsudh.blogspot.com/p/gallery-of-native-plants_17.html
_________________
- http://www.anbg.gov.au/fern/life_cycle.html
- http://amerfernsoc.org/lernfrnl.html
- http://www.calflora.org/cgi-bin/specieslist.cgi?where-genus=Polypodium
We
welcome your comments (below). You can
also send your questions to: mothernaturesbackyard10@gmail.com
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