Observation 21491: Polystichum acrostichoides
When: 2009-05-30
No herbarium specimen

Notes: Looks like some kind of rust attacking this fern.

Proposed Names

60% (2)
Recognized by sight: That has got to be the most fertile Polystichum I’ve ever seen! But those are “just” the sporangia. The peltate indusia are clearly visible. Maybe P. lonchitum or is that more northern?
Used references: A Field Manual of the Ferns & Fern-Allies by David Lellinger
94% (3)
Eye3 Eyes3
Recognized by sight: Christmas Fern

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Gotta love the things that blur the boundary between kingdoms!
By: Jason Hollinger (jason)
2009-06-01 10:25:40 PDT (-0700)

Yeah, I agree, it sure does look like a Chrysomyxa! And for whatever it’s worth, I couldn’t find any photos on the web of any Polystichum where the sporangia completely covered the undersurface of the pinnae as in yours. (I have seen it in other genera of fern, but none with peltate indusia…)

I concur…
By: R. E. Tulloss (ret)
2009-06-01 08:25:28 PDT (-0700)

I agree that these very nice photographs show a fern (unmolested) doing its reproductive thing. Christmas ferns are very common all over my home town (including in my back yard).


Thanks Jason
By: Dan Molter (shroomydan)
2009-05-31 14:36:56 PDT (-0700)

I thought it might be just the fern sporangia, but it looked similar to some rusts I have encountered this spring so I posted it.

Created: 2009-05-31 13:11:09 PDT (-0700)
Last modified: 2009-05-31 13:11:09 PDT (-0700)
Viewed: 84 times, last viewed: 2016-10-25 17:59:38 PDT (-0700)
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