Chorizanthe diffusa
Chorizanthe valida
diffuse spineflower
Sonoma spineflower
basal;
petiole 0.2–1.8(–2) cm;
blade oblanceolate, 0.3–2 × 0.1–0.4 cm, villous.
basal or nearly so;
petiole 1–3 cm;
blade broadly oblanceolate, 1–2.5(–5) × 0.4–0.8(–1.2) cm, usually villous.
rather dense with secondary branches suppressed, white to greenish;
bracts 2, similar to leaf blades at proximal nodes only reduced, short-petiolate, becoming linear and aciculate at distal nodes, acerose, 0.3–2 cm × 1–4 mm, awns absent.
with secondary branches suppressed, grayish;
bracts 2, similar to proximal leaf blades only reduced, short-petiolate, becoming linear and aciculate at distal nodes, acerose, 1–3 cm × 6–10 mm, awns absent.
1, mostly greenish, cylindric, not ventricose, 2–2.5 mm, with thin to broad and then conspicuous white or pinkish to purple, scarious margins extending nearly full length of awn, not corrugate, villous-hirsute;
teeth spreading to divergent, equal, 0.5–1 mm, awns uncinate with longer ones 1–2 mm, anterior one mostly 2 mm, alternating with shorter (0.5–1 mm) ones.
1, grayish, cylindric, not ventricose,3–4(–4.5) mm, with white, scarious margins between teeth, finely corrugate, thinly pubescent;
teeth erect, equal, 0.3–0.7(–1) mm;
awns straight, with longer ones 0.7–1.3 mm and anterior one mostly 1.3 mm, these alternating with shorter, 0.5–1(–1.2) mm ones.
exserted;
perianth bicolored with floral tube lemon-yellow and tepals white, campanulate, 2.5–3 mm, glabrous;
tepals connate ca. 1/3 their length, monomorphic, oblong, acute to obtuse and entire apically;
stamens 3–9, slightly exserted;
filaments distinct, 1.5–2 mm, glabrous;
anthers yellow, oval, 0.3–0.4 mm.
exserted;
perianth bicolored with floral tube white and tepals white to lavender or rose, cylindric, (4–)5–6 mm, pubescent on proximal 1/2;
tepals connate 1/4 their length, dimorphic, oblong, truncate and erose to denticulate, sometimes individual lobes entire, 2-lobed or even cuspidate apically, those of outer lobes longer and wider than inner ones;
stamens 9, included;
filaments distinct, 2–4.5 mm, glabrous;
anthers pink to red or maroon, oblong, 0.6–0.8(–1) mm.
dark brown, globose-lenticular, 2–2.5 mm.
light brown, lenticular-globose, 3–4.5 mm.
= 38, 40, 42.
Chorizanthe diffusa
Chorizanthe valida
The involucral margins of Chorizanthe diffusa vary greatly. In some individuals, the white margins are barely visible. Plants with the margins of the involucre are predominantly white have been designated var. nivea. A full gradation between the extremes may be observed in most populations, although in coastal sands var. nivea is often the dominant expression. Diffuse spineflower occurs near the coast and in the Coast Ranges of central California.
Chorizanthe diffusa has been shown to inhibit carcinogen-induced preneoplastic lesions in a mouse mammary-organ culture model. This inhibitory activity is known to correlate with cancer chemopreventive effects in full-term models of tumorigenesis (see H. S. Chung et al. 1999).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Of conservation concern.
Chorizanthe valida may be distinguished by the highly colored involucre. The teeth and bases of awns are bright red. The awns then quickly transform to a bright ivory and this color dominates nearly the length of each awn. In the more inland populations (now extirpated), the awns observed in the old collections appear to be a straw color. It is not known if this is an artifact of age or potentially significant. Sonoma spineflower is now known only from grassy fields south of Abbott’s Lagoon in the Point Reyes area of Marin County (L. Davis and R. J. Sherman 1990, 1992). The last collection from Sonoma County was made at Sebastopol in 1907. The type, collected in 1841, apparently was gathered near Fort Ross, also in Sonoma County. This species is federally listed as endangered.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
WildflowerSearch
iNaturalist
USDA Plants Database
