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Perityle ajoensis

(Ajo Rock-Daisy)

Overview

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Critically Endangered

Threat status

Interesting Facts

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Common Names

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Common Names in English:

Ajo Rock-Daisy, Ajo Rockdaisy

Description

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Family Compositae

The largest family of flowering plants , the Compositae (Asteraceae), comprising about 1,100 genera and more than 20,000 species and characterized by many small flowers arranged in a head looking like a single flower and subtended by an involucre of bracts. A head may consist of both ray flowers and disk flowers, as in the sunflower, of disk flowers only, as in the burdock, or of ray flowers only, as in the dandelion.

Genus Perityle

Annuals , perennials , subshrubs , or shrubs , 2-45(-75) cm (glabrous or hairy , often gland-dotted). Stems erect to pendent. Leaves mostly cauline; often proximally opposite, distally alternate; petiolate or sessile; blades usually 3-lobed, ultimate margins entire, toothed , or lobed . Heads radiate or discoid , borne singly or in corymbiform arrays. Involucres campanulate , cylindric , funnelform , or hemispheric , 3-15 mm diam. Phyllaries persistent , 5-28 in (1-) 2(-3) series (distinct , linear to ovate , equal or subequal , flat or keeled , glabrous or hairy, apices obtuse , acute, or attenuate). Receptacles flat or convex , pitted , epaleate. Ray florets 0, or (1-) 3-18, pistillate , fertile ; corollas cream, yellow, or white (showy or rudimentary ). Disc florets 5-200, bisexual , fertile; corollas cream, yellow, or white, tubes shorter than or nearly equal to cylindric, funnelform, or campanulate throats, lobes 4, ± deltate (acute; stamens 4; style branches flattened, linear, usually tapering to fine, minutely hairy tips). Cypselae (black) flattened to subcylindric , linear to oblanceolate or obovate (margins ± calloused and glabrous, hairy, or ciliate , faces usually hairy, sometimes glabrous) ; pappi 0, or persistent or falling, of 1-35 bristles plus callous crowns or hyaline scales . x = 17, 19.

Species 66: United States, Mexico, South America.

Most species of Perityle are rock-dwelling subshrubs exhibiting geographic speciation ; most are found in the eroded mountain and basin region of the southwestern United States.[1]

Physical Description

Species Perityle ajoensis

Ajo rock daisy [source]

Perennials or subshrubs , to 30 cm; usually densely short-tomentose. Leaves (proximally opposite, distally alternate) : petioles 3-10 mm; blades deltate, ovate , or suborbiculate, 5-15 × 5-15 mm, margins shallow-crenate to dentate . Heads borne singly or (2-10) in loose , corym-biform arrays, 7-9 × 6-9 mm. Peduncles 5-15 mm. Involucres campanulate to hemispheric . Phyllaries 15-20, oblanceolate to broadly lanceolate, 4-5 × 0.8-1.8 mm. Ray florets 0. Disc florets 20-45; corollas yellow, tubes 1-1.2 mm, throats tubular to narrowly funnelform , 1.3-1.6 mm, lobes 0.4-0.6 mm. Cypselae narrowly suboblong to oblanceolate, 2.5-3.5 mm, margins prominently calloused, short-hairy; pappi of 1(-2) stout bristles 1.8-2.8 mm. 2n = 34. [source]

Habit: Subshrub , Forb/herb

Flowers: Bloom Period: February, March, April, May, June, July, August, September, October.

Habitat

Crevices of rocky canyon walls and cliff faces ; of conservation concern; 800-1200 m [2].

Biology

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Reproduction

Duration: Perennial

Taxonomy

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Notes

Name Status: Accepted Name . Latest taxonomic scrutiny: 15-Mar-2000

Similar Species

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Members of the genus Perityle

ZipcodeZoo has pages for 55 species, subspecies, varieties, forms, and cultivars in this genus:

P. aglossa (Bluff Rock Daisy) · P. ajoensis (Ajo Rock-Daisy) · P. ambrosiifolia (Lace-Leaf Rock Daisy) · P. angustifolia (Narrow-Leaved Rockdaisy) · P. bisetosa (Two-Spike Rock Daisy) · P. bisetosa var. appressa (Twobristle Rockdaisy) · P. bisetosa var. bisetosa (Twobristle Rockdaisy) · P. bisetosa var. scalaris (Twobristle Rockdaisy) · P. californica (California Rock Daisy) · P. cernua (Nodding Rock Daisy) · P. ciliata (Ciliate Rockdaisy) · P. cinerea (Gray Rock Daisy) · P. cochisensis (Cochise Rock Daisy) · P. congesta (Compact Rock Daisy) · P. coronopifolia (Arizona Rockdaisy) · P. dissecta (Dissected Rockdaisy) · P. emoryi (Emory Rockdaisy) · P. fosteri (Foster's Rock-Daisy) · P. gilensis (Fish Creek Rockdaisy) · P. gilensis var. gilensis (Fish Creek Rockdaisy) · P. gilensis var. salensis (Salt River Rockdaisy) · P. gracilis (Grass Leaf Rock Daisy) · P. huecoensis (Hueco Mountains Rockdaisy) · P. incana (Perityle) · P. intricata (Delicate Rock-Daisy) · P. inyoensis (Inyo Rock Daisy) · P. lemmonii (Lemmon's Rock-Daisy) · P. lindheimeri (Bluffdaisy) · P. lindheimeri var. halimifolia (Lindheimers Rockdaisy) · P. lindheimeri var. lindheimeri (Lindheimer's Rockdaisy) · P. megalocephala (Bighead Rockdaisy) · P. megalocephala var. megalocephala (Limestone Rockdaisy) · P. megalocephala var. oligophylla (Small-Leaved Rockdaisy) · P. microglossa (Mazanilla Bronca) · P. microglossa var. microglossa (Shortray Rockdaisy) · P. microglossa var. saxosa (Shortray Rockdaisy) · P. parryi (Heartleaf Rockdaisy) · P. quinqueflora (Five Flower Rock Daisy) · P. rupestris (Leafy Rockdaisy) · P. rupestris var. albiflora (Leafy Rockdaisy) · P. rupestris var. rupestris (Leafy Rockdaisy) · P. saxicola (Fish Creek Rock Daisy) · P. specuicola (Alcove Rockdaisy) · P. stansburii (Standbury's Rockdaisy) · P. stansburyi (Stansbur's Rockdaisy) · P. staurophylla (New Mexico Rockdaisy) · P. staurophylla (Barneby) Shinners var. homoflora T.K. Todsen (New Mexico Rockdaisy) · P. staurophylla var. homoflora (New Mexico Rockdaisy) · P. staurophylla var. staurophylla (New Mexico Rockdaisy) · P. tenella (Springdale Rockdaisy) · P. turneri (Turner's Rockdaisy) · P. vaseyi (Margined Rockdaisy) · P. villosa (Hanaupah Laphamia) · P. vitreomontana (Glass Mountain Rockdaisy) · P. warnockii (River Rock-Daisy)

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 February 28, 2008:

Identifiers

Footnotes

  1. Sharon C. Yarborough, A. Michael Powell "Perityle". in Flora of North America Vol. 21 Page 317, 333, 334. Oxford University Press. Online at EFloras.org. [back]
  2. "Perityle ajoensis". in Flora of North America Vol. 21 Page 324, 331. Oxford University Press. Online at EFloras.org. [back]
Last Revised: 7/15/2012