Chorizanthe uniaristata |
Chorizanthe orcuttiana |
|
---|---|---|
one-awn spineflower |
Orcutt spineflower, Orcutt's spineflower, San Diego spineflower |
|
Habit | Plants spreading or ascending, 0.2–0.6(–0.8) × 0.5–4(–5) dm, appressed-pubescent. | Plants prostrate, 0.1–0.5 × 0.3–2(–2.5) dm, villous. |
Leaves | basal; petiole 0.5–2 cm; blade oblanceolate, 0.5–1.5(–2) × 0.2–0.8 cm, thinly pubescent. |
basal; petiole 1–2 cm; blade narrowly oblanceolate, 0.5–1.5 × 0.2–0.35(–0.5) cm, thinly pubescent. |
Inflorescences | with involucres in small open clusters 0.5–1.5 cm diam., greenish to grayish or reddish; bracts 2, sessile, usually leaflike, oblanceolate to elliptic, 0.5–1.5 cm × 1.5–5 mm, gradually reduced and becoming scalelike at distal nodes, linear, aciculate, acerose, 0.4–1.2 cm × 1–2(–3) mm, awns straight, 1.5–4 mm. |
with involucres in small clusters 0.5–1 cm diam., greenish; bracts 2, sessile, unequal, 1 laminar and oblanceolate, 0.3–1 cm × 1–3 mm, awnless, this opposite linear, acicular, greatly reduced, 0.1–0.2 cm × 0.3–0.6 mm bract terminated by short, straight awn 0.6–1 mm. |
Involucres | 3–10, grayish to reddish, urceolate, slightly ventricose basally, 2–3 mm, without scarious or membranous margins, slightly corrugate, densely grayish-pubescent; teeth widely spreading to divergent, unequal, 0.3–0.5 or 3–6 mm; awns straight or uncinate, unequal, with longer anterior one straight, 2.5–5.5 mm, others spreading, uncinate, 0.3–0.5 mm. |
1, greenish, campanulate, 3-ribbed, 0.8–2 mm, faintly corrugate, pubescent; teeth 3, equal, 1.8–2 mm; awns uncinate, 0.6–1 mm. |
Flowers | included or only slightly exserted; perianth bicolored with floral tube greenish white and tepals white, cylindric, 2–3 mm, sparsely pubescent; tepals connate 2/3 their length, dimorphic, linear-oblong, those of outer whorl spreading, narrowly oblong, 1.5 times longer than those of inner whorl, rounded but with minute cusp or 3 teeth apically, those of inner whorl erect to slightly spreading, acute, entire apically; stamens 3, included; filaments distinct, 1–2 mm, glabrous; anthers white, ovate, 0.4–0.5 mm. |
1, included to slightly exserted; perianth yellow, cylindric, 1.5–1.8 mm, densely pubescent abaxially; tepals connate ca. 1/2 their length, monomorphic, narrowly oblanceolate, obtuse to truncate, entire apically, slightly spreading; stamens 9, slightly exserted; filaments distinct, 0.5–0.8 mm, glabrous; anthers reddish, ovate, 0.2–0.3 mm. |
Achenes | brown, globose-lenticular, 2–3 mm. |
dark brown, lenticular, 2–2.2 mm. |
2n | = (78), 80, (82). |
= (76, 78), 80, (84). |
Chorizanthe uniaristata |
Chorizanthe orcuttiana |
|
Phenology | Flowering Apr–Jul. | Flowering Mar–May. |
Habitat | Sandy to gravelly talus or clay flats and slopes, mixed grassland and chaparral communities, pine-oak woodlands | Sandy soil, mesas and hills near coast, coastal scrub communities |
Elevation | 800-1900 m (2600-6200 ft) | 60-200 m (200-700 ft) |
Distribution |
CA
|
CA |
Discussion | Chorizanthe uniaristata is scattered in the Inner Coast Ranges and across the Transverse and Tehachapi ranges to the southern Sierra Nevada. One-awn spineflower is a polyploid, but whether an autopolyploid or an autoallopolyploid has not been determined. It has the smallest meiotic chromosomes observed by C. B. Hardham (1989). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Chorizanthe orcuttiana is known from a few populations on coastal mesas and hills near San Diego, San Diego County. It is federally listed as endangered. The species is an octoploid that may well have resulted from an ancient hybridization and doubling of chromosomes involving C. procumbens and C. polygonoides var. longispina. The Orcutt spineflower grows in soft, white sand; C. procumbens and C. polygonoides var. longispina are restricted to gravelly sites. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 460. | FNA vol. 5, p. 467. |
Parent taxa | Polygonaceae > subfam. Eriogonoideae > Chorizanthe > subg. Amphietes > sect. Ptelosepala | Polygonaceae > subfam. Eriogonoideae > Chorizanthe > subg. Amphietes > sect. Acanthogonum |
Sibling taxa | ||
Name authority | Torrey & A. Gray: Proc. Amer. Acad. Arts 8: 195. (1870) | Parry: Proc. Davenport Acad. Nat. Sci. 4: 54. (1884) |
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