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Chorizanthe biloba

(Two-Lobe Spineflower)

Overview

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Vulnerable

Threat status

Interesting Facts

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Common Names

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Common Names in English:

Two-Lobe Spineflower, Twolobe Spineflower

Description

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Family Polygonaceae

Herbs, shrubs , or small trees , sometimes monoecious or dioecious. Stems erect , prostrate , twining , or scandent , often with swollen nodes, striate , grooved , or prickly. Leaves simple , alternate, rarely opposite or whorled , petiolate or subsessile ; stipules often united to a sheath (ocrea) . Inflorescence terminal or axillary , spicate , racemose, paniculate , or capitate. Pedicel occasionally articulate . Flowers small, actinomorphic , bisexual , rarely unisexual . Perianth 3-6-merous, in 1 or 2 series, herbaceous, often enlarged in fruit or inner tepals enlarged, with wings , tubercles , or spines. Stamens usually (3-) 6-9, rarely more; filaments free or united at base ; anthers 2-loculed, opening lengthwise; disk annular (often lobed ) . Ovary superior, 1-loculed; styles 2 or 3, rarely 4, free or connate at lower part. Fruit a trigonous , biconvex , or biconcave achene; seed with straight or curved embryo and copious endosperm.

About 50 genera and 1120 species: worldwide, but primarily N temperate with a few species in tropical regions ; 13 genera (two endemic) and 238 species (65 endemic) in China.[1]

Genus Chorizanthe

Herbs [or subshrubs ], annual [or perennial ]; taproot slender to stout. Stems prostrate or decumbent to erect , pubescent ; aerial flowering stems arising [at nodes of caudex branches, at distal nodes of aerial stems or] directly from the root , decumbent to erect, slender [to stout and solid, not disarticulating in ringlike segments], sometimes disarticulating at each node. Leaves persistent or quickly deciduous, basal and rosulate or basal and cauline, alternate; petiole present; blade linear to oblanceolate or spatulate , entire apically. Inflorescences terminal , cymose or capitate, uniparous due to suppression of secondaries; branches open and spreading or erect, typically trichotomously branched at proximal node, otherwise dichotomous, sometimes brittle and disarticulating into segments, round , pubescent [or rarely glabrous ]; bracts mostly 2, opposite, sometimes numerous , whorled , distinct , leaflike to subulate or linear, occasionally awn-tipped, thinly pubescent (sometimes appressed ), hirsute , villous , strigose , or tomentose , rarely woolly-floccose or minutely glandular . Peduncles absent. Involucres 1-6+ per node, 3-6-ribbed, tubular , cylindric to urceolate or turbinate to campanulate ; teeth 3, 5, or 6, awn-tipped. Flowers bisexual , 1(-2) per involucre, pedicellate ; perianth white to yellow or pink to rose-pink, red, maroon or purple, cylindric, funnelform , or campanulate when open, cylindric when closed , glabrous or pubescent abaxially; tepals (5-) 6, connate 3 their length , monomorphic or dimorphic , entire, emarginate , or lobed to laciniate apically; stamens 3, 6, or 9, or variously 3-9; filaments distinct or connate into staminal tube , sometimes adnate to floral tube , glabrous or pubescent; anthers maroon to red or cream to white or yellow, oval to oblong ; styles erect to spreading. Achenes included , light brown to dark brown or black, not winged , lenticular , globose-lenticular, or 3-gonous, glabrous. Seeds: embryo straight or curved . x = 10.

Species 50: North America (including Mexico), South America.

Like Eriogonum, Chorizanthe is the basal element in its own subtribe , Chorizanthineae Reveal. Nonetheless, recent molecular data indicate that Chorizanthe is embedded within Eriogonum (A. S. Lamb Frye, pers. comm. ), meaning that either all species of the Chorizanthineae should be moved to Eriogonum, or Eriogonum should be fragmented into several genera. Obviously, therefore, all of the segregate genera that follow could be merged into Chorizanthe, and this was common practice until 1989. A key factor still unresolved is the relationship between the perennial species of Chorizanthe (including the type of the genus) and Eriogonum. The traditional assumption is that Eriogonum and Chorizanthe represent independent lines of evolution from a basal, diploid (n = 10) ancestor that is now extinct . A corollary to this assumption is that this divergence occurred during the Eocene and the perennial spineflowers were successfully introduced into southern South America, whereas the wild buckwheats€”lacking a ready means for long-distance dispersal€”failed to make the trip . Thus, it is possible that the perennial members of Chorizanthe represent a genus distinct from the annuals treated here (33 of the 41 annuals occur in the flora area, the rest are in Mexico or in South America). In that case, our annual members (if not submerged into Eriogonum) would be called Acanthogonum Torrey.

The segregate genera allied to Chorizanthe, like those allied to Eriogonum, differ primarily in their involucres. Aristocapsa and Dodecahema, with haploid chromosome numbers of 14 and 17, respectively, are difficult to associate with any extant member of Chorizanthe (mainly n = 19, 20, 38, 40). Centrostegia, Lastarriaea, Mucronea, and Systenotheca all appear much more akin to Chorizanthe. A point of origin can be suggested only for Lastarriaea, namely Chorizanthe interposita Goodman of central Baja California, Mexico. C. D. Hardham (1989) reported a range of gametic numbers from single individuals. Until somatic counts are made, the primary chromosome numbers of some species remain uncertain.

J. L. Reveal and C. B . Hardham (1989b) divided the annual species of Chorizanthe genus into three subgenera : subg. Amphietes (39 species), and subg. Eriogonella and subg. Quintaria (one species each). The first is divided into four sections (Ptelosepala, Acanthogonum, Fragile, and Clastoscapa Reveal & Hardham), all but the last of which are found in our region. Some sections were divided into subsections, which are not treated here.

The approximately nine perennial species of subg. Chorizanthe occur only in arid regions of Chile and Argentina.[2]

Physical Description

Species Chorizanthe biloba

Plants erect or infrequently spreading , (0.5-) 1-3(-4) × 1-3(-4) dm, pubescent . Leaves basal; petiole 0.5-3 cm; blade oblance-olate, 1-3(-5) × 0.4-1(-1.3) cm, thinly pubescent. Inflorescences with involucres in open clusters 2-4(-6) cm diam., greenish or reddish to purplish; bracts 2-3 at proximal node, usually leaflike, often with whorl of sessile bracts ca. midstem, elliptic , 0.5-1.5 cm × 2-6 mm, gradually becoming lanceolate to elliptic, 0.2-2 cm × 1.5-8 mm, at distal nodes scalelike, linear and aciculate , acerose , awns straight, 1-3 mm. Involucres 3-10 or more, grayish or reddish, urceolate and slightly ventricose basally, 4-6 mm, without scarious or membranous margins , slightly corrugate, strigose ; teeth erect to spreading, unequal, 1-2 mm; awns mostly uncinate , 0.5-2 mm, with longer anterior one straight, mostly 2 mm. Flowers exserted; perianth bicolored with floral tube white to yellow and tepals red, maroon, or dark purple, cylindric , (4.5-) 5-6 mm, sparsely pubescent; tepals connate 2 their length , dimorphic , obovate , those of outer whorl spreading, slightly longer than those of inner whorl, 2-lobed, emarginate , or subacute apically, those of inner whorl erect, obtuse , fimbriate apically; stamens 9, exserted; filaments distinct , 4-5 mm, glabrous ; anthers yellow to golden, oblong , 1.2-1.8 mm. Achenes brown, globose-lenticular, 4-4.5 mm. 2n = (34, 36, 38), 40, (42, 44, 46). [source]

Unlike the serpentine species Chorizanthe palmeri and C. ventricosa, C. biloba occurs on gravelly or clayey soils. Those species and C. obovata can be quickly differentiated by carefully examining the colors, shapes , and modifications of the tepals. Immature specimens can be difficult to place, but a combination of geographic location and edaphic features can often enable accurate identification of even fragmentary material . [source]

Taxonomy

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Synonyms

Chorizanthe palmeri S. Watson var. biloba (Goodman) Munz • Chorizanthe palmeri S.Watson var. biloba (Goodman) Munz

Notes

Publishing author : Goodman Publication : Ann. Missouri Bot. Gard. 21: 73 1934 [12 Apr 1934]

Similar Species

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Members of the genus Chorizanthe

ZipcodeZoo has pages for 54 species, subspecies, varieties, forms, and cultivars in this genus:

C. angustifolia (Narrowleaf Spine-Flower) · C. biloba (Two-Lobe Spineflower) · C. biloba var. biloba (Twolobe Spineflower) · C. biloba var. immemora (San Benito Spineflower) · C. blakleyi (Blakey's Spine-Flower) · C. brevicornu (Brittle Spineflower) · C. brevicornu var. brevicornu (Brittle Spineflower) · C. brevicornu var. spathulata (Brittle Spineflower) · C. breweri (Brewer's Chorizanthe) · C. clevelandii (Cleveland's Spineflower) · C. corrugata (Wrinkled Chorizanthe) · C. cuspidata (San Francisco Spineflower) · C. cuspidata var. cuspidata (San Francisco Bay Spineflower) · C. cuspidata var. villosa (Coast Spineflower) · C. diffusa (Diffuse Spineflower) · C. douglasii (Douglas Spineflower) · C. douglasii var. albeus (Douglas´s Spineflower) · C. fimbriata (Fringed Spineflower) · C. fimbriata var. fimbriata (Fringed Spineflower) · C. fimbriata var. laciniata (Fringed Spineflower) · C. howellii (Howell Chorizanthe) · C. leptotheca (Peninsular Spineflower) · C. membranacea (Clustered Spineflower) · C. obovata (Spoon-Sepal Spineflower) · C. orcuttiana (Orcutt's Spineflower) · C. palmeri (Palmer's Spineflower) · C. parryi (Orcutt Spine-Flower) · C. parryi parryi var. parryi (San Bernardino Spineflower) · C. parryi var. fernandina (San Fernando Valley Chorizanthe) · C. parryi var. parryi (San Bernardino Spineflower) · C. polygonoides (Knotweed Spineflower) · C. polygonoides longispina (Knotweed Spineflower) · C. polygonoides var. longispina (Long-Awned Spineflower) · C. polygonoides var. polygonoides (Knotweed Spineflower) · C. procumbens (Prostrate Spineflower) · C. pungens (Monterey Spineflower) · C. pungens var. hartwegiana (Ben Lomond Spineflower) · C. pungens var. pungens (Monterey Spineflower) · C. rectispina (One-Awned Chorizanthe) · C. rigida (Devil's Spineflower) · C. robusta (Robust Spineflower) · C. robusta var. hartwegii (Robust Spineflower) · C. robusta var. robusta (Robust Spineflower) · C. spinosa (Mojave Spineflower) · C. staticoides (Statice Spineflower) · C. stellulata (Starlet Spineflower) · C. uniaristata (One-Awn Spineflower) · C. valida (Sonoma Spineflower) · C. ventricosa (Priest Valley Spineflower) · C. watsonii (Five-Tooth Spineflower) · C. wheeleri (Santa Barbara Spineflower) · C. xanti (Pinyon Spineflower) · C. xanti var. leucotheca (Riverside Spineflower) · C. xanti var. xanti (Riverside Spineflower)

More Info

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Further Reading

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Notes

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Contributors

Data Sources

Accessed through GBIF Data Portal November 19, 2007:

Identifiers

Footnotes

  1. Anjen Li, Bojian Bao, Alisa E. Grabovskaya-Borodina, Suk-pyo Hong, John McNeill, Sergei L. Mosyakin, Hideaki Ohba & Chong-wook Park "Polygonaceae". in Flora of China Vol. 5 Page 277. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
  2. James L. Reveal "Chorizanthe". in Flora of North America Vol. 5. Oxford University Press. Online at EFloras.org. [back]
Last Revised: 7/16/2012