Grindelia in Monterey County, California

Just some notes for now - a place to assemble information on local Grindelia taxonomy. Inspired by observations like this one: https://www.inaturalist.org/observations/117539735 and associated comments by @yerbasanta.

Initially, the emphasis is on separating hirsutula and platyphylla, particularly in light of a tricky population on Fort Ord near Watkins Gate Rd.

Taxonomic history:

  • Styermark (1934) wrote the main key that splits Grindelia into perhaps over 100 taxa worldwide - with perhaps more splitting than is now considered warranted. Stother & Wetter writing for FNA Vol. 20 (2006) explictly call Steyermark's granularity into question. Styermark's key is very long, and consequently difficult to follow if one is just interested in a particular geography. For example, it splits G. stricta var. platyphylla into two "forms" that occur in completely different parts of the key.
  • Keck (1959) was perhaps (?) the first to distill Styermark down to California - including 12 species. G.stricta var. platyphylla occurs under the name G. latifolia ssp. platyphylla. The split between hirsutula and platyphylla is at the top of Keck's key.
    " A. Tips of phyllaries erect or spreading, some gradually curved but not sharply reflexed. --> hirsutula etc.
    AA. Tips of phyllaries (at least of some middle and outer ones) sharply reflexed or looped). --> stricta etc."

  • Lane (1992, 1993) was probably the next author to tackle a Californian key. First Lane published a 1992 paper that combined some Gridelia taxa together to arrive at 6 species. Then Lane authored the TJM1 treatment in 1993, in which the hirstula/platyphylla split also occurred at the top level, but upon different characters to those used by Keck. Thus:
    "1. Pappus awns > 0.3 mm wide at base, minutely serrate, V-shaped in X-section; lvs +- fleshy; coastal. --> stricta var. platyphylla, etc.
    1'. Pappus awns < 0.3 mm wide at base, entire, U-shaped in X-section or flat; lvs gen not fleshy; inland. --> hirustula etc."
    Lane also suggested various platyphylla hybrids e.g. that maritima may have arisen from platyphylla x hirsutula.

  • Matthews (1997) includes: hirsutula (vars h. and maritima), latifolia, sticta var. platyphylla, and camporum. The split between hirsutula and platyphylla is made at the first couplet, based on phyllary hairiness (platyphylla glabrous) and shape, leaf fleshiness, and head width. The details are helpful. The part about phyllary hairiness is interesting, because it doesn't seem to show up much in other keys.
  • Stother & Wetter (2006, FNA) lumped platyphylla under hirsutula, not as a distinct infra-species taxon, but offered some infra-specific notes on what had to date been called "platyphylla", including reference to Lane's notes on hybrids: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250066812
  • Moore (2012, TJM2) recognizes about 8 species, and several subspecies. The hirsutula/platyphylla split is made near the top, on the basis of habitat and leaf fleshiness:
    " 2. Plants of dunes, salt marshes, coastal bluffs, tidal flats, sloughs; leaves ± fleshy. --> platyphylla etc.
    2' Plants of fields, grassland, woodland, serpentine soils, disturbed areas, or interior wetlands; leaves not fleshy; widespread (absent from Suisun delta). --> hirsutula etc."

  • Moore also wrote a dissertation (2010) and two papers (2012, 2014) on Grindelia genetics. These are a great read, but they don't directly inform the question of how to ID a plant that could be hirsutula or stricta var. platyphylla. One or two relevant points from Moore et al.'s results are: (i) hirsutula and stricta var. platyphylla are closely related, (ii) geographic variation is pronounced in the genus, and variation is marked between populations and limited within populations.
  • Matthews & Mitchell (2015) generall follow Moore (2012) (i.e. not the original Matthews (1997) edition). They include four taxa: angustifolia, platyphylla, hirsutula, and camporum. There's some good info in their text.
  • Yeager & Mitchell (2016) just include platyphylla, but theirs is not intended to be an exhuastive list for the County.
  • Styer (2019) suggests most Fort Ord Grindelia are platyphylla, and the presence of hirsutula is uncertain. This make sense when you realize that most Fort Ord Grindelia occur west of Hwy 1 in the most dune-like habitats. But it leaves interior Fort Ord Grindelia in question - the inland plants are on ancient dunes, and in grasslands that are somewhat interior.

Summarizing all this for use on Fort Ord in Monterey County, California, if one were to simultaneously accept Keck (1959), Lane (1993), and Moore (2012), it seems that for a plant to be hirsutula, it should have: phyllaries not sharply reflexed; awns that are narrow, entire, and U-shaped or flat; leaves (gen.) not fleshy and a location that is perhaps more like interior grassland than coastal dune. On the other hand, if one were to dismiss all but the most recent author, a hirsutula would simply need to be interior and non-fleshy-leaved.

Note that POWO currently subsumes platyphylla under hirsutula, but iNat recognizes platyphylla as a distinct taxon. The two are supposed to align, but this is not always the case. In such situations, I think it is best to ID to the taxa available in iNat (i.e. platyphylla or hirsutula, depending on characters), and if a lumping is deciding later in iNat, the IDs can be automatically lumped as well.

Disclaimer: I haven't searched beyond the literature I cited. There may be pertinent literature that I haven't looked at yet.

Maybe some other day I'll dig out the text from a few of the regional floras for Monterey, Santa Cruz, and San Luis Obispo counties...

由使用者 fredwatson fredwatson2023年06月27日 17:07 所貼文

評論

The more I read, the less clear this seems for the local examples. I think the fact that so many authors have come at so many different angles, without any clear consensus might reflect that this taxa needs more study (possibly in terms of awn morphology, cypselae, or maybe even response to KOH as for Lasthenia(?)), for individuals such as those we've been discussing and examining.

It's possible (a hunch) that the taxa is relatively recently undergoing an adaptive radiation, so that there may be many varieties (or even subspecies) of a single species which have may have been assigned a taxonomic rank too early. It's also possible there are many more species than currently circumscribed, but that genomic analysis is needed to differentiate them due to morphological overlap.

You likely already saw this, but in the eFlora page under the genus Grindelia*, there are some nice descriptions of phyllary differences in terms of degrees of recurving, which I found somewhat murky for a while. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=114086

Even TJM mentions:
"Note: Variable. Morphologically intermediate plants common where species ranges overlap. Strother & Wetter treated all California species except Grindelia squarrosa and Grindelia fraxinipratensis in Grindelia hirsutula."
https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=451

Further notes/post-script
*from source above:
"Within and among populations of grindelias, some morphologic traits appear to vary more from plant to plant than in most genera of composites. M. P. Dunford (1964) reported grindelias he had tested to be "essentially self-incompatible" and (1986) stated, "...Grindelia species are outcrossing and self-incompatible...." Some patterns of variation within Grindelia are similar to those found in genera characterized by apomictic seed production (e.g., local morphologic variants such as discoid plants in otherwise radiate taxa, hairy plants in otherwise glabrous taxa, narrow-leaved plants in otherwise broad-leaved taxa, etc.)."

**( from http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250066812):
"As circumscribed here, Grindelia hirsutula includes 30 or more reputedly distinct, local, regional, or ecotypic facies that have been named at species or infraspecific rank. Locally, such facies are easily recognized; in a broad view, they intergrade with other facies and are parts of a heterogeneous continuum. Taxonomies that have attempted to recognize the facies as distinct "taxa" have led to almost as many specimens determined as "intermediate" as are assigned to the named "taxa.""

Personally, I'm usually a splitter rather than a lumper, so I'm happy to continue examining the genus for any conclusive morphological characteristics, but currently there are some local individuals that elude clear classification based on the current flora descriptions (at least as I read them).

I'll see if I can dip into the literature to see if there's been any major developments since 1934 (Steyermark)/1986 (Dunford)

發佈由 yerbasanta 超過 1 年 前

Great notes. Thanks.

發佈由 fredwatson 約 1 年 前

Thank you both for these well researched and helpful comments.

發佈由 aparrot1 9 個月 前

My summary, (nothing new that you didn't already say above)
Calflora lists 59 records of this species in Monterey County (as of 8/30/23): https://www.calflora.org/entry/observ.html?track=m#srch=t&lpcli=t&taxon=Grindelia+hirsutula&chk=t&cch=t&cnabh=t&inat=r&cc=MNT
https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=3107
Plants of Monterey County: an Illustrated Field Key, 2nd edition, Matthews and Mitchell, 2015, pp. 42-43.
Flora of Fort Ord: Monterey County, California, David Styer, 2019, p. 44
There are 3 Grindelia listed in CCo per Jepson eFlora:
Grindelia hirsutula
Grindelia stricta var. angustifolia
Grindelia stricta var. platyphylla
Jepson eFlora Key to Grindelia in CCo (Central Coast of California)
https://keybase.rbg.vic.gov.au/keys/show/3414?filter_id=55b17b2b4727a

發佈由 aparrot1 9 個月 前

I have not dabbled in California Grindelia as they have been bewildering to me so far, but there was a genus revision done by Bartoli and Tortosa in 2011. Revision of the North American Species of Grindelia (Asteraceae). Annals of the Missouri Botanical Garden v. 98. I imagine the treatment may be similar to Moore as they were coauthors on her 2012 paper.

發佈由 rymcdaniel 3 個月 前

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