Confusing comb-burs

It's that time of year when the comb-burs (Pectocarya spp.) are popping. Four of the local species are darn near identical vegetatively; three of them are fairly common locally (northeastern Maricopa County) and one is rare. This observation shows the differences in the fruit of the three more common ones, and this one is of the local rarity, P. setosa.
Some description based on a guide I wrote some time ago:
P. heterocarpa: Tips of nutlets bent slightly forwards. Marginal teeth are not spreading; teeth are fewer to missing on one nutlet.
P. recurvata: Nutlets curved backwards. Marginal teeth on fruit regularly spaced, hooked. This is the most common species of the three locally.
P. platycarpa: Swollen margin. Teeth irregularly spaced, hooked, with fattened base; teeth smaller and more numerous at the tips of the nutlets.
And for a bonus here is its slightly larger cousin, Harpagonella arizonica. Fruit differ from the four-nutlet, x-shaped plan of the pectocaryas.

הועלה ב-מרץ 4, 2021 12:15 לפנה"צ על ידי stevejones stevejones

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stevejones

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מרץ 30, 2013

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Location accurate, dates not. Posted to accompany this journal post.

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stevejones

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אפריל 4, 2013

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Photographed off trail while under permit from the City of Scottsdale

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I started this entry a couple of hours ago but was rudely interrupted by the wind removing the roofing from my back porch.

פורסם על-ידי stevejones לפני בערך 3 שנים

Very informative post, Steve.

Sorry to know you home's been damaged by this anomalous weather. These winds will serve to spread stinknet seed even further.

פורסם על-ידי mjplagens לפני בערך 3 שנים

Thanks, Mike. Yes, you're likely right about the stinknet. More bad news.
The good news (if any) is that I was planning to replace the roofing later this year or next. This just forces the issue.

פורסם על-ידי stevejones לפני בערך 3 שנים

Thanks for the detailed descriptions, @stevejones . Your photo comparisons were great and now with these further details, I might actually feel a little more confident identifying them. Well... probably not but it's no reflection on your teaching skills :-D

Like Mike, I was also thinking about invasive seeds spreading :-(

Bummer regarding your roof. (I've spent most of the morning gathering up things I forgot to batten down). Take good care of your back while repairing!

פורסם על-ידי ezpixels לפני בערך 3 שנים

Hah, just linked to the observations so they're included. Had to cheat on the dates!

פורסם על-ידי stevejones לפני בערך 3 שנים

As I mentioned on the observation, I'm eager to see Moth Comseed! Very cool and pretty straightforward ID wise :-)

פורסם על-ידי ezpixels לפני בערך 3 שנים

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