For my PhD research through California
Botanic Garden, I'm studying the genus Malacothamnus
which has several conflicting taxonomic treatments and many
. I am using a combination of morphometric analyses,
Restriction site Associated DNA Sequencing (RAD-Seq), comparative
phenology, and extensive field evaluations to resolve the taxonomy of the
and evaluate the conservation status of each
taxon. This work will hopefully be completed by 2022. I hope to fill in
this web page with more resources on the genus as I have time.
I've created an iNaturalist project to help
with this research which you can visit here
iNaturalist users have been a great help in documenting locations,
variation, and phenology in the genus Malacothamnus
observations are welcome. If you want help identifying Malacothamnus
this is a good place to post your observations as I regularly check this
site. Tips on what to photograph for a good ID are here
If you post Malacothamnus
observations on iNaturalist, follow these
to share your coordinates with the project to make your
observations much more useful.
While I'm putting very little time into it,
a secondary iNaturalist project looking at the animals found interacting
Observations for this project are welcome as well.
is an alternative to iNaturalist for data collection on plants in
California. I monitor these observations as well, but less regularly.
Calflora is where I post most of my plant observations. If you want a
reference population for a rare (or any) Malacothamnus
is a good place to go as iNaturalist obscures locations of rare plants. An
example query for my observations of M. davidsonii
If you visit any of these locations, make an updated observation on
Calflora or iNaturalist. This helps track how the populations are changing
Calflora is the first place I to go for
California plant information as it ties together data from many other
sources including the Jepson eflora, CCH, Calphotos, CNPS, and
iNaturalist. Like other sources of data on Malacothamnus, it is
good to be cautious at present though. For example, many locations on the
Calflora Malacothamnus maps use herbarium specimens and many of
those specimens are currently misidentified. This will eventually be fixed
when I resolve the taxonomy and can annotate these specimens.
Treatments and Identification
As mentioned above, there are several
conflicting treatments. They are all problematic one way or another mostly
due to lumping, splitting, and a lot of overlapping morphological
characters. Treatments follow below. If you want help with identification
beyond the treatments, see the iNaturalist Project section above. Calphotos
is also useful to check IDs, but some photo IDs could be questionable.
I'm mostly following the Kearney
at present until I can resolve the taxonomic questions and
produce something better. Kearney was more of a splitter, but this
treatment still actually lumped several taxa from previous treatments.
This treatment seems to follow the current evidence the most closely and
includes rare taxa lumped by other treatments. The keys aren't perfect,
but better than nothing. The Munz
mostly follows Kearney and is a bit simplified, so this is
another good option. These treatments are missing both Malacothamnus
. The Munz treatment is missing taxa from Mexico.
Do not use the Flora of North America or
Jepson treatments. The 1993 Jepson Manual and Flora of North America
treatments by David Bates are pretty much identical to each other. The
taxa in these treatments were way over-lumped making them very problematic
in relation to rare taxa. To the author's credit, he does say that the
Kearney treatment is as justifiable as his. Likewise, the current Jepson
Manual treatment is best avoided. Author Tracey Slotta made some good
progress in splitting back out some lumped taxa based on morphological
analyses, but her key is also problematic in various ways.
Draft regional keys and guides: