Buddleja davidii.
Family Scrophulariaceae.
It, and its numerous cultivars, are among the most commonly cultivated in Australia.
It is naturalised, and becoming a significant weed, in some states.
It is a variable species depending on where it is growing.
Erect, semi-deciduous, multi-stemmed shrubs up to 3 m or small trees to 5 m.
Arching stems, square in cross section, are densely hairy when young but become hairless when older.
Opposite, narrowly ovate to lanceolate leaves, on short stalks, are up to 20 cm long.
The upper surface is dark green and the pale lower surface is densely covered in hairs.
The blade tips are pointed and the edges are finely toothed.
The small round to ovoid stipules are up to 6 mm long.
Inflorescences are terminal, or axillary near the branch ends.
Branched or unbranched, they mature from the base up and can be up to 30 cm long.
Up to 5 cm wide they are densely covered in small flowers on very short or no stalks.
The bisexual flowers are up to 14 mm long and 5 mm across.
The narrow, bell-shaped, 3 mm long calyx has the lower half of the 4 sepals fused into a tube.
The lower 3/4 of the 4 petals are fused into a corolla tube up to 1 cm long.
The 2 to 3 mm long lobes spread outwards.
The corolla is mauve to purple with orange nectar guides in the throat.
Cultivars add white, red and yellow.
The 4 short stamens are inserted near the middle of the corolla tube.
The superior ovary has 2 locules and a style around 1 mm long with a club-shaped stigma.
The narrowly ovoid fruit capsules, up to 10 mm long by 2 mm, mature from green to brown.
They may be smooth or have stellate hairs.
The brown seeds, around 3 mm long by 0.5 mm, have wings at both ends.
There are a number of sub-species and around 100 cultivars with pink, dark purple, reddish-purple,
yellow and white flowers.
Cultivars include Royal Red, Ice Profusion, Blue Chip, Purple Haze, Black Knight, Cran Raz,
Purple Haze, Grand Cascade, Magenta Munchkin, Lilac Cascade, Princess Pink and Pink Cascade.
The “Buzz” series of cultivars are compact, dwarf shrubs with normal sized inflorescences around 15 cm long.
Included are “Buzz Hot Raspberry”, “Buzz Lavender”, “Buzz Midnight”, “Buzz Purple” and “Buzz Blue Sky”.
J.F.
