Picris rigida

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.

Tribe Lactuceae

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.

Genus Picris

Annuals , biennials, or perennials , 10-100+ cm; tap- or fibrous-rooted, sometimes rhizomatous . Stems usually 1, erect , branched distally, hirsute to hispid or setose (hair tips often 2[-4]-hooked). Leaves basal and cauline (mostly cauline at flowering) ; basal ± petiolate , distal sessile; blades oblong , ovate , or lanceolate to oblanceolate or linear , margins entire or sinuate-dentate to pinnately lobed (faces hirsute to hispid or setose, hair tips 2[-4]-hooked). Heads usually in ± corymbiform arrays. Peduncles not inflated distally, sometimes bracteate . Calyculi of 8-13+, lanceolate to lance-linear bractlets (sometimes ± intergrading with phyllaries). Involucres campanulate to urceolate , 6-12+ mm diam. (sometimes larger in fruit). Phyllaries (8-) 13+ in 1-2 series (reflexed in fruit), lanceolate to lance-linear (± flat or navicular proximally, sometimes each ± enfolding its subtended floret), equal, margins often scarious , apices acute. Receptacles flat to convex , ± pitted , glabrous , epaleate. Florets 30-100+; corollas yellow, often reddish abaxially. Cypselae homomorphic [heteromorphic], reddish brown [dark brown], bodies ± fusiform [compressed-ellipsoid], not beaked [beaks ± developed], ribs 5-10, faces transversely rugulose , glabrous; pappi falling, of 30-45+, whitish to stramineous , subequal , barbellulate to plumose bristles [scales ] in 2-3+ series (basally connate , falling together). x = 5.

Species ca. 40: introduced ; Europe, Asia, n Africa; also introduced in tropical Africa, Australia.[1]

Taxonomy

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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: Spermatopsida () - Brongniart, 1843
        Subclass: Asteridae () - Takhtajan, 1967
        Superorder: Campanulanae () - Takhtajan Ex Reveal, 1992
        Order: Asterales () - Lindley, 1833
        Family: Compositae () - Giseke, 1792, nom. cons., nom. alt.
        Subfamily: Cichorioideae ()
        Tribe: Lactuceae ()
        Subtribe: Hypochaeridinae ()
        Genus: Picris () - C. Linnaeus, 1753 - Oxtongue [Greek picris, bitter or sharp; allusion unclear]
        Specific epithet: rigida - Ledeb.
        Botanical name: - Picris rigida Ledeb.