Vascular Plants of North Carolina
Account for Floss-flower - Ageratum houstonianum   P. Miller
Members of Asteraceae:
Only member of Ageratum in NC.
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Section 6 » Order Asterales » Family Asteraceae
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AuthorP. Miller
DistributionThere are several collections from NC, but most are from cultivated plants, such as the NC State College greenhouse, a home address in Raleigh, "in cult" at Biltmore, etc. Two may represent escapees: Forsyth County, Winston-Salem, 1 Oct 1940, P. Schallert s.n. (CM, no image or other data); and Surry County, roadside, "escapee?", 1 Sept 2000, no collector sn (SC). The CM record is skeletal, so a look at the specimen label would help a great deal. FNA and BONAP map it for NC, without naming counties.

Native of Mexico and C.A.; in N.A. MA, CT, NC to FL and TX; OH.
AbundanceVery rare.
PhenologyFlowering and fruiting July-August.
IdentificationFloss-flower, often just called Ageratum in the horticulture trade, is a familiar garden plant, but it seldom escapes. It looks like a Eupatorium, but the heads are lavender-blue. It is similar to Conoclinium coelestinum, but that native plant grows from long slender rhizomes (vs. fibrous roots) and the involucres (flower head bracts) are non-glandular (vs. glandular-pubescent in the non-native Ageratum).
Taxonomic Comments
Other Common Name(s)Ageratum, Bluemink
State RankSE
Global RankGNR
State Status
US Status
USACE-agcpFACU link
USACE-empFACU link
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