Scientific Name:
Ageratina altissima
'Chocolate'
Pronunciation:
ad-jur-uh-TY-nuh al-TISS-ih-muh
Common Name:
white snakeroot
Family Name:
Asteraceae
Plant Type:
Herbaceous perennial
Key ID Features:
Leaves opposite, dark green, lanceolate to elliptic-ovate (like stinging nettle), most blades 6-1(-15)2cm long x 5-9cm wide; margin serrate, apex acuminate, most petioles 3-6cm long; heads small and fluffy, bright white disk florets only (rays florets absent), arranged in loose corymbs 7-10cm across.
Habit:
Upright
Form:
Oval - vertical
Texture:
Medium - coarse
Mature Height:
0.7 - 1.3m
Mature Spread:
0.6 - 1.0m
Growth Rate:
Fast
Origin:
Garden origin, U.S. - northeast
Hardiness Rating:
Zone 4: (-34 to -29 °C)
Exposure:
Full sun
Soil/Growing Medium:
Humus rich, Well-drained
Landscape Uses:
Perennial border, Summer interest, Woodland margin
Additional Info:
Leaf Morphology:
Form:
Simple
Arrangement:
Opposite
Texture/Venation:
Soft flexible, Heavily veined, Pinnate venation
Surfaces:
Glabrous
Colour in Summer:
Dark-green, Dark-red
Shapes:
Ovate
Apices:
Acuminate
Bases:
Attenuate
Margins:
Serrate
Inflorescence Type:
Head (capitulum), Corymb-like
Flower Morphology:
Flowers perfect
Number Of Petals:
5
Corolla Shape:
Tubular
Ovary Position:
Inferior
Colour (petals):
Showy, White
Flower Time at Peak:
Aug, Sep, Oct
Additional Info:
Ray florets absent
Fruit Type:
Cypsela (achene + calyx)
Fruit Colour:
Silver
Fruiting Time:
Sep, Oct
Bark or Stem Colour:
Red, Brown
Organ Modifications:
Rhizomes
Propagation:
Seed, Division - below ground parts
Maintenance:
Medium
Pest Susceptibility:
Leaf miner insect (Pest resistant, Disease resistant, Deer resistant)
