HIERACIUM

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Most plants referable to Hieracium are apomictic (reproducing from asexually produced seeds). Apomictic reproduction often results in perpetuation of morphologic variants at populational and regional levels. Temptation to name such variants as species has proven irresistible to some botanists; upward of 9,000 species names have been published in Hieracium. Circumscriptions of “species” in Hieracium seem to be more artificial than in most genera of composites. Under these circumstances, I feel it would be irresponsible to recognize any infraspecific taxa here. For the most part, the “species” recognized here are those that have been recognized in local and regional floras of the past 50 or so years. Accepted names and/or changes in synomymies for some species reflect changes suggested by J. H. Beaman (1990), A. Cronquist (1980), and E. G. Voss (1972–1996, vol. 3).

Facts about "HIERACIUM"
apex shapeobtuse +, acute + and acuminate +
array architecturecorymbiform +, paniculiform +, thyrsiform +, umbelliform + and racemiform +
blade shapeelliptic +, lanceolate +, oblanceolate +, oblong + and spatulate +
bractlet shapedeltate +, lanceolate + and linear +
bractlet variabilityintergrading +
bristle architecturebarbellulate +
bristle colorationwhite +, sordid +, stramineous + and rufous +
bristle fusiondistinct +
bristle sizeunequal +
bristle variabilityequal +
calyculus count0 + and of 3-13-16+ +
chromosome count9 +
corolla colorationyellow +, white +, ochroleucous +, tinged with cyan or tinged with red +, orange +, drying + and purplish +
cypsela colorationred-brown +, black + and tan +
cypsela shapecolumnar +, prismatic +, urceolate +, fusiform + and beaked +
face external textureglabrous + and hairy +
head arrangementsingly + and in corymbiform , paniculiform , thyrsiform , umbelliform , or nearly racemiform arrays +
indument architecturecomplex +
involucre shapehemispheric +, campanulate + and cylindric +
leaf architecturepetiolate + and sessile +
leaf positionbasal + and cauline +
margin external texturescarious +
margin shapeentire +, denticulate +, dentate +, laciniate + and pinnatifid +
margin sizelittle +
pappus durationpersistent +
pappus fragilityfragile +
peduncle architecturebracteate +
peduncle shapeinflated +
phyllary orientationreflexed +
phyllary shapelanceolate + and linear +
phyllary sizesubequal + and unequal +
receptacle architectureepaleate +
receptacle external textureglabrous +
receptacle prominence or shapeflat +
receptacle reliefpitted +
rib count10 +
rootstock architecturebranched +
rootstock internal texturewoody +
stem architecturebranched +
stem count1 +
stem external textureglabrous + and hairy +
stem orientationerect +
stem shapescapiform +
whole organism architecturetaprooted +
whole organism life styleperennial +