genus Holocarpha

Member of tarweeds and allies (tribe Madieae)
sunflower family (family Asteraceae)
dicots (class Magnoliopsida)
flowering plants (subphylum Angiospermae)

There are no other wild species of this genus in the bay area.

pit-gland tarweed
Holocarpha virgata

pit-gland tarweed
Holocarpha virgata

anthers ± red to dark purple
ray flowers 3–8; disk flowers 9–25+
uncommon in the east bay

santa cruz tarplant
Holocarpha macradenia

anthers ± red to dark purple
ray flowers 8–16; disk flowers 40–90
rare near Santa Cruz, Mt. Tam

heermann’s tarweed
Holocarpha heermannii

heermann’s tarweed
Holocarpha heermannii

anthers yellow to ± brown [usually yellow?]
stem notably stalked-glandular
phyllaries each with 25–50 pit-gland-tipped outgrowths and minutely sessile- or stalked-glandular and puberulent or minutely bristly
heads 1 or in panicle- or raceme-like clusters
uncommon in the east bay

san joaquin tarweed
Holocarpha obconica

anthers yellow to ± brown
stem resinous distally, not notably stalked-glandular
phyllaries each with (0)5–15(20) pit-gland-tipped outgrowths and generally glabrous or minutely sessile- or stalked-glandular (bristly)
heads in flat-topped or panicle-like clusters
rare at Grant, Del Valle, Mt. Diablo

2 observed taxons / 2 unobserved taxons / 1 key

Chris’s observations: 4 (all are research grade)

Locations:

Mt. Diablo SP: 3
Henry Coe SP

Months:

Oct.: 1
Nov.: 3

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Taxon info: iNaturalist – Calflora – Jepson eFlora – FNA

Bay Area species: iNaturalist – Calflora