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.
The Lactuceae are a tribe of closely related genera of the sunflower family that are easily recognized because the flowering heads are composed of wholly of ligulate florets that are usually 5-lobed. Another very distinguishing feature is the milky sap . Although not apparent without magnification, the pollen is distinctive in that the spines are more or less restricted to discrete ridges or flanges on the surface of the grain. In other members of the family the spines are distributed more or less evenly over the surface of the pollen grain . The pappus usually consists of scales or stiff hairs . -- Gerald D. Carr.
Annuals [biennials], 15-150 cm; fibrous-rooted. Stems 1, erect
or branched, glabrate
to sparsely or densely pilose
. Leaves basal and cauline (not in rosettes) ; narrowly winged-petiolate; blades
to suborbiculate (thin), margins
, or lyrate-pinnatifid proximally (terminal lobes
larger than laterals
glabrate to sparsely hirsute
; distal sessile, lanceolate, reduced). Heads in open, corymbiform
to thyrsiform arrays. Peduncles (slender) slightly inflated
. Calyculi of 4-5 subulate
or scalelike, glabrous
. Involucres cylindric
, 2-5 mm diam. Phyllaries 8-10 in 1 series, linear-oblong, subequal
, (strongly keeled
) margins green, not scarious
, apices acute, faces glabrous. Receptacles flat, smooth
, glabrous, epaleate. Florets 8-15; corollas yellow. Cypselae dimorphic
(outer much longer
than inner), tan to golden brown, subcylindric
to slightly compressed
, not beaked
, ± 20-ribbed, glabrous; pappi 0. . = 7.
Species 1: introduced ; Europe, Asia.
Lapsana formerly included about 9 species, some from eastern Asia. Based on cladistic analysis of morphologic characters, the eastern Asian species have been removed to Lapasanastrum, a strongly supported monophyletic group characterized by spreading phyllaries and distinctive fruit anatomy (J. H. Pak and K . Bremer 1995).
- Whittaker & Margulis,1978
- Haeckel, 1866
- Cavalier-Smith, 1981
- Sinnott, 1935 ex Cavalier-Smith, 1998
- Vascular Plants
- Brongniart, 1843
- Takhtajan, 1967
- Takhtajan Ex Reveal, 1992
- Lindley, 1833
- Giseke, 1792, nom. cons., nom. alt.
- Tribe: Lactuceae ()
- Subfamily: Cichorioideae ()
- Family: Compositae () - Giseke, 1792, nom. cons., nom. alt.
- Order: Asterales () - Lindley, 1833
- Superorder: Campanulanae () - Takhtajan Ex Reveal, 1992
- Subclass: Asteridae () - Takhtajan, 1967
- Class: Spermatopsida () - Brongniart, 1843
- Subphylum: Euphyllophytina ()
- Phylum: Tracheophyta () - Sinnott, 1935 ex Cavalier-Smith, 1998 - Vascular Plants
- Subkingdom: Viridaeplantae () - Cavalier-Smith, 1981
- Kingdom: Plantae () - Haeckel, 1866 - Plants
Members of the genus Lapsana
ZipcodeZoo has pages for 2 species, subspecies, varieties, forms, and cultivars in this genus:
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- Pak, J. H. and K. Bremer. 1995. Phylogeny and reclassification of the genus Lapsana (Asteraceae: Lactuceae). Taxon 44: 13-21.
- Brands, S.J. (comp.) 1989-present. The Taxonomicon. Universal Taxonomic Services, Zwaag, The Netherlands. Accessed January 12, 2012.
- Zipcode Zoo Species Identifier: 1844133