Interesting Facts
Description
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 Omalotheca
Perennials
, 2-70 cm (fibrous-rooted, rhizomatous
, not stoloniferous
). Stems usually 1, erect
(branched from bases
or distally, woolly-tomentose to sericeous
). Leaves basal (persistent
in rosettes) and cauline; alternate; sessile; blades
mostly narrowly lanceolate to oblanceolate
, bases cuneate, margins
entire, faces
bicolor or concolor
, abaxial
white to gray, thinly tomentose
, adaxial
white to grayish and sericeous to thinly woolly
or greenish and glabrate
. Heads disciform
, in spiciform
or subcapitate
arrays. Involucres campanulate
to turbinate
, 5-6 mm.
Phyllaries in 2-3 series, stramineous
to brownish (sometimes mottled
; hyaline
, stereomes
not glandular
), unequal, chartaceous
toward apices. Receptacles flat to concave
, smooth
, epaleate. Peripheral (pistillate
) florets 35-70+ (more numerous
than bisexual
) ; corollas purplish or whitish. Inner (bisexual) florets 3-4; corollas purplish or whitish, distally purplish or reddish. Cypselae obovoid
to cylindric
or fusiform
, sometimes slightly compressed
, faces strigillose
(hairs
not myxogenic, lengths
6-12 times diams.) and papillate
(carpopodia forming minute stipes) ; pappi falling readily, of 15-25 distinct
(falling separately) or basally connate
(falling together), barbellate
bristles
in 1 series. x = 14.
Species 8-10: mostly Eurasian; three species reaching North America in native
distribution (Omalotheca sylvatica perhaps not native, see below).
The species of Omalotheca have been placed in subg. Omalotheca (capitulescences
of 1-10 heads
, cypselae compressed-obovoid, and pappus bristles distinct and falling separately) and subg. Gamochaetiopsis Schultz-Bipontinus & F. W. Schultz (capitulescences of 10-100 heads, cypselae cylindric, and pappus bristles basally connate and falling together).[1]
Taxonomy
- Domain:
Eukaryota
(
)
- Whittaker & Margulis,1978
- eukaryotes
- Kingdom:
Plantae
()
- Haeckel, 1866
- Plants
- Subkingdom:
Viridaeplantae
()
- Cavalier-Smith, 1981
- Phylum:
Tracheophyta
()
- Sinnott, 1935 ex Cavalier-Smith, 1998
- Vascular Plants
- Subphylum:
Euphyllophytina
()
- Class:
Magnoliopsida
()
- Brongniart, 1843
- Dicotyledons
- Subclass:
Asteridae
()
- Takhtajan, 1967
- Superorder:
Campanulanae
()
- Takhtajan Ex Reveal, 1992
- Order:
Asterales
()
- Lindley, 1833
- Family:
Compositae
()
- Giseke, 1792, nom. cons., nom. alt.
- Subfamily:
Asteroideae
()
- Tribe:
Gnaphalieae
()
- Subtribe:
Gnaphaliinae
()
- Genus:
Omalotheca
()
- Cassini in F. Cuvier, Dict. Sci. Nat. ed. 2. 56: 218. 1828.
- Arctic Cudweed
- Specific epithet:
caucasica
- (Sommier & Levier) Czerep.
- Botanical name: - Omalotheca caucasica (Sommier & Levier) Czerep.
- Specific epithet:
caucasica
- (Sommier & Levier) Czerep.
- Genus:
Omalotheca
(
- Subtribe:
Gnaphaliinae
(
- Tribe:
Gnaphalieae
(
- Subfamily:
Asteroideae
(
- Family:
Compositae
(
- Order:
Asterales
(
- Superorder:
Campanulanae
(
- Subclass:
Asteridae
(
- Class:
Magnoliopsida
(
- Subphylum:
Euphyllophytina
(
- Phylum:
Tracheophyta
(
- Subkingdom:
Viridaeplantae
(
- Kingdom:
Plantae
(
Synonyms
Gnaphalium Caucasicum • Gnaphalium caucasicum Somm. & Levier
Similar Species
Members of the genus Omalotheca
ZipcodeZoo has pages for 3 species, subspecies, varieties, forms, and cultivars in this genus:
O. norvegica (Norwegian Arctic Cudweed) · O. supina (Alpine Arctic Cudweed) · O. sylvatica (Wood Cudweed)
More Info
- Search for Pictures: images.google.com
- Search for Scholarly Articles: Google Scholar
- Search using Scientific Name and Vernacular Names: All the Web | AltaVista Canada | AltaVista | Excite | Google | HotBot | Lycos
- Search using Specialized Databases: GenBank | Medline | Scirus | CISTI/CAL | Agricola Periodicals | Agricola Books
Further Reading
- Nesom, G. L. 1990b. Taxonomic summary of Omalotheca (Asteraceae: Inuleae). Phytologia 68: 241-246.
Notes
Contributors
- Brands, S.J. (comp.) 1989-present. The Taxonomicon. Universal Taxonomic Services, Zwaag, The Netherlands. Accessed January 11, 2012.
Identifiers
- Biodiversity Heritage Library NamebankID: 9186625
- Global Biodiversity Information Facility Taxonkey: 15179379
- Globally Unique Identifier: urn:lsid:ipni.org:names:984674-1
- Zipcode Zoo Species Identifier: 3113110
Footnotes
- Guy L. Nesom "Omalotheca". in Flora of North America Vol. 19, 20 and 21 Page 58, 387, 429, 438, 439. Oxford University Press. Online at EFloras.org. [back]
