Asteraceae

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Asteraceae (Compositae, “composites,” or “comps”) have long been recognized as a

   natural group, and circumscription of the group has never been controversial (although some
   authors have divided the traditional family into three or more families). A. Cronquist (1981)
   placed Asteraceae as the only family in the order Asterales within subclass Asteridae,
   associated with the Gentianales, Rubiales, Dipsacales, and Calycerales and relatively distant
   from Campanulales. On recent molecular phylogenetic data, the Angiosperm Phylogeny Group (2003;
   see references there for details; classification abbreviated APGII hereafter) has suggested that
   Asteraceae are better treated as part of a more widely defined Asterales within the asterids II
   informal clade (or campanulid clade; see W. S. Judd and R. G. Olmstead 2004). Judd and Olmstead
   summarized the higher-order relationships of Asteraceae as follows (in order of decreasing
   inclusiveness; synapomorphies in parentheses): asterids (ovules unitegmic and tenuinucellate,
   iridoid chemistry); core asterids (sympetaly, stamen number equal to petal number, stamen
   epipetaly, mostly 2–3-carpellate gynoecia); campanulids (early sympetaly), comprising eight
   unassigned families plus Aquifoliales, which is sister to Dipsacales, Apiales, and Asterales
   (last three sharing frequently inferior ovaries, polyacetylenes); and Asterales, which appears
   to be sister to Dipsacales-Apiales (K. Bremer et al. 2004). The order Asterales (valvate petals,
   lack of apotracheal parenchyma, storage of inulin, ellagic acid present, and, possibly, the
   presence of a plunger or brush pollen presentation mechanism) now includes the following
   families (fide APGII): Alseuosmiaceae, Argophyllaceae, Calyceraceae, Campanulaceae (optionally
   including Lobeliaceae), Goodeniaceae, Menyanthaceae, Pentaphragmaceae, Phellinaceae,
   Rousseauaceae, and Stylidiaceae. Within Asterales, Asteraceae is part of a clade (corollas with
   more or less fused lateral veins joining midvein near lobe apices, thick integuments, no
   endosperm haustorium) with the Menyanthaceae (cosmopolitan with Southern Hemisphere genera)
   basal to a more nested clade (inferior ovaries, possibly connate anthers, pollen exine with
   bifurcating columellae) comprising Asteraceae, Goodeniaceae (mainly Australia), and Calyceraceae
   (South America), the last being the immediate sister to Asteraceae (highly modified, persistent
   calyces, corolla venation patterns, unilocular and uniovulate gynoecia, pollen with intercolpar
   depressions, specialized fruits). Aggregation of flowers into heads with involucres appears to
   have been a parallel phenomenon in Calyceraceae and Asteraceae, given the determinate nature of
   the former and indeterminate (racemose) organization of the latter. Some traits typical of
   Asteraceae predate evolution of the family as a distinct clade. Relationships of Asteraceae and
   Calyceraceae have been discussed by M. H. G. Gustafsson and Bremer (1995). Synapomorphies of the
   Asteraceae clade include: calyces modified to structures called pappi, anthers connate (forming
   tubes) and styles modified to function as brushes in a specialized pollen presentation
   mechanism, ovaries each containing a single basal ovule, and production of sesquiterpene
   lactones.
Facts about "Asteraceae"
anther dehiscenceintrorse +
anther fusionconnate +
appendage external texturehirsute +
appendage reliefpapillate +
array architecturecymiform +, corymbiform +, racemiform + and spiciform +
array developmentdeterminate + and indeterminate +
band architecturecontinuous +
band count1 +
band habitstigmatic +
base shapedecurrent +
blade architecturesimple + and compound +
bract derivationinvolucral +
branch architectureappendaged +
branch shapetruncate +
caudex internal texturewoody +
corolla architecture3-5-merous +, actinomorphic +, zygomorphic +, kinds + and liguliflorous +
corolla architecture or arrangementradiant +
corolla architecture or shapediscoid + and disciform +
embryo coursestraight +
enation shapesubulate +
face positionabaxial + and adaxial +
filament fusiondistinct +
filament fusion or positioninserted +
floret architecturepistillate +, staminate + and neuter +
floret reproductionbisexual + and neutral +
fruit architecturewinged + and alate +
fruit characterdispersed +
fruit internal texturedry +
fruit shapebeaked + and rostrate +
head architecturesessile + and each borne on a peduncle +
head arrangementsingly + and in usually determinate , rarely indeterminate , arrays +
head countsingle +
head developmentindeterminate +
leaf architecturestipulate +, petiolate + and sessile +
leaf arrangementalternate + and opposite +
line arrangementseparate + and contiguous +
line count2 +
line habitstigmatic +
margin shapepinnatifid + and palmatifid +
ovary architecture2-carpellate + and 1-locular +
ovary positioninferior +
ovule count1 +
ovule fixationattached +
ovule orientationanatropous +
papilla habitstigmatic +
pappus countsingle +
pericarp fragilitytough +
pericarp widththick +
petal fusionconnate +
receptacle architecturepaleate +, receptacular + and epaleate +
receptacle external texturebristly +, hairy + and bearing subulate enations +
receptacle shapeflat +, convex +, conic + and columnar +
root internal texturefibrous +
seed architectureexalbuminous +
seed count1 +
sepal ordinarymodifed +
stamen arrangementalternate +
stamen count5 +
stem internal texturefleshy +
stem locationunderground +
stem orientationerect +, prostrate + and ascending +
style architecture2-branched + and branched +
style count1 +
style fusionconnate + and distinct +
style reliefringed +
whole organism life styleannual +, biennial + and perennial +