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Roldana barba-johannis

Interesting Facts

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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.

Tribe Senecioneae

The Senecioneae are a tribe of closely related genera that can be recognized most readily by the nature of the pappus and the involucral bracts or phyllaries. The phyllaries are basically in one well developed, often partially or wholly connate series of equal length that closely envelope the head . Frequently there are a few, very much smaller and mostly randomly distributed, often necrotic-tipped bracts near the base of the main series. The pappus is of fine, soft, often pure white capillary hairs . Heads may be either discoid or radiate . -- Gerald Carr.

Genus Roldana

Perennials or subshrubs [shrubs , or trees ], [20-]60-100(-300) [-800] cm (caudices woody, fibrous-rooted, often woolly ). Stems single or clustered, erect (glabrous or arachnose and glabrescent [tomentose to lanate ]). Leaves mostly cauline (at flowering) ; alternate; petiolate ; blades pinnati-palmately [pinnately or palmately] nerved, suborbiculate (proximal ) to ovate or oblong (distal) [deltate, elliptic , lanceolate, orbiculate, or ovate], sinuately to angularly lobed (± polygonal) [palmately, pinnately, or not lobed], ultimate margins serrate to denticulate (lobes and denticles apiculate ) or entire, abaxial faces glabrous or arachnose [tomentose to lanate] and glabrate , adaxial glabrous or glabrate [tomentose to lanate]. Heads radiate [disciform or discoid ], in corymbiform or paniculiform arrays (peduncles usually arachnose). Calyculi 0 or of 1-3(-5) [-13+] (linear [filiform to foliaceous ]) bractlets . Involucres campanulate [hemispheric to cylindric or funnelform ], 3-5[-20+] mm diam. Phyllaries persistent , (5-) 8-13+ in 2 series, erect, distinct , lanceolate or lance-linear to linear (± navicular ), equal, margins ± scarious . Receptacles flat, alveolate (margins of sockets raggedly toothed ), epaleate. Ray florets [0 or 3-]5-8, pistillate , fertile ; corollas yellow or yellow-orange [whitish or ochroleucous ] (laminae usually oblong to elliptic). Disc florets 6-30[-100+], bisexual , fertile; corollas yellow or yellow-orange [whitish or ochroleucous], tubes shorter to longer than funnelform to campanulate throats, lobes 5, recurved, deltate to lance-ovate; style branches: stigmatic areas continuous, apices rounded-truncate. Cypselae ± columnar , [5- or] 10-ribbed, puberulent (between ribs ) [glabrous]; pappi persistent (fragile), of 40-80+, white, barbellulate bristles in 1 series. x = 30.

Species ca. 50: sw United States, Mexico, Central America.[1]

Taxonomy

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Notes

Name Status: Accepted Name .

Comment: Data Providers: IPNI, MesoAmericana, Tropicos. GCC LSID: urn :lsid:compositae.org:names:9A782790-98D0-434B-A2F3-D7975E4A1B9C

Last scrutiny: 15-Aug-09

Similar Species

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Members of the genus Roldana

ZipcodeZoo has pages for 2 species, subspecies, varieties, forms, and cultivars in this genus:

R. hartwegii (Carl Mason's Ragwort) · R. petasitis (California Geranium)

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 16, 2008:

Identifiers

Footnotes

  1. A. Michele Funston "Roldana". in Flora of North America Vol. 20 Page 542,620. Oxford University Press. Online at EFloras.org. [back]
Last Revised: 2012-07-23