ferns

My starting point is Pacific Coast Fern Finder by Keator and Heady.

Questions:

1. Why do some sword ferns have fiddleheads and others not?
   I think this question has the same answer: why are some sword ferns smaller, lighter green, with no fiddleheads?
   The answer to both must be maturity. Because I haven't found a different sword fern species common in PNW, and everything else matches sword fern.

2. I looked at a lot of pinnae this week (early May) and didn't see a lot of sori. Looking mostly like at lady fern. Fronds already grown out to a couple feet long. When do sorus form?

https://www.kruckeberg.org/fall-is-fern-reproduction-time/

Since many spores ripen in late summer, this is a good time to be checking the back sides of your fern fronds. When they are ripe, they generally look plump, and raised up. If the sori have already shed their spore, they will appear flat and dark.

1. Need to see an example of when one frond is completely sterile, and another isn't.

Deer fern photo of mature male frond w/o sori. Also: 1-pinnately divided frond. Deer browse in winter because they stay green. Frond narrows both toward tip and toward base.
https://intocascadia.com/2016/10/28/an-easy-guide-to-ferns-of-the-pacific-northwest/

The unique part is they are fully connected to the stem at the leaf base instead of on mini stems. Licorice Fern is fully connected too (see Bonus section) but it only grows in single fronds, not clusters, and only on vertical surfaces like cliffs.

Licorice fern is "also unique in that it only grows in single fronds (which are connected by a rhizome running through the moss) rather than in a cluster of fronds like most ferns."

Holly ferns are 1-divided fronds (like sword and deer ferns) and have holly shaped leaf.

1. I believe I read somewhere that pinnae shape can reflect frond shape... tapering.
   Lady fern "are widest in the middle and then taper to the base."

Spreading wood fern. 1-divided fronds (I could see). Even if margin is quite serrated. The indusia are supposed to be horseshoe shape, can't tell from blow up phone photo. (Hard to use good camera on sori w/o breaking off pinnae.) Not sword fern because no hilt or "projection at base of pinnae." Finally, broad triangle shaped frond. The thing that was quite distinct, and noticed a lot of, was not mentioned in the fern finder was the consistent asymmetry of pinnae length for base pair. (http://nativeplantspnw.com/spreading-wood-fern-dryopteris-expansa/ does point out assymetry)
https://www.inaturalist.org/observations/46522985

Posted on May 12, 2020 11:00 PM by williamkimzey