July 26, 2019

Case study: Hymenopappus filifolius

This begins as an unknown. It was collected 7-28-2019 on Mt. Lemmon near radio ridge. At least I think that is where I collected it. I spotted a different Asteraceae from the H. hoopesii that is everywhere up there and rushed to collect some. I really should take notes. And I should note things that I will wish I knew (like if leaves are alternate or opposite). Photos would cover some bets too. Since I am just studying these and then tossing them out, it is not so critical. If someday I collect specimens to press and offer to the herbarium, I definitely need to slow down and get systematic about taking notes.

It is a yellow Asteraceae. Several flowers on each head. Thready pinnate leaves. Flowers are in a cyme like structure.

The flowers are fascinating under the microscope! This is a great microscope plant. It looks like it has short ray flowers, but actually the tips of the phyllaries are recurved and turn yellow!

This is an interesting plant. My first time seeing it and my first success keying out an unknown Asteraceae!! What a treat.

Key this out using Arizona Flora

We start on page 830. 
Corollas bilabiate? No.
All flowers ligulate? No.
Rays present? No.
Pappus none? Yes.  group C
Now page 831 for group C 
Heads unisexual, monoecious? No.
Flowers all hermaphrodite? Yes.
Heads with only 1 or 2 flowers? No.
Receptacle chaffy? No.
Achenes strongly compressed or plump?  Plump.
Phyllaries with conspicuous yellow tips? Yes!  Hymenopappus (91)
Now page 919 for Hymenopappus 
Heads radiate, rays white? No.
Leaves entire or pinnatifid? Pinnatifid.
Corolla teeth half as long as throat? No, mine are very short.
Plant scapose or leafy stemmed? Scapose -- H. lugens.
This keyed out nicely without confusion.

Comments

This has been renamed H. filifolius, perhaps H. filifolius var. lugens. It is in Frank Roses book on page 35. The head was very interesting with the Achenes beginning to turn brown and the flowers are not sessile on the achene, but have a short stem
Have any comments? Questions? Drop me a line!

Tom's Plant pages / tom@mmto.org