Fuchsia excorticata (kōtukutuku) is a
gynodioecious and
deciduous species of tree in the family
Onagraceae, reaching up to in height with a twisted
trunk, which is up to in diameter. It branches within several metres from the base, forming a spreading
canopy.
F. excorticata is the largest member of the genus
Fuchsia; while most species grow as shrubs or small trees, this species has evolved in New Zealand to reach a much greater height.
F. excorticata is noted for its shredding
bark, which is a copper, orange, to reddish-brown in colour, and naturally peels off into thin sheets of paper, revealing the smooth pale green
cambial layer in the inner bark. The
leaves are up to long and wide. They are
glabrous and slightly
strigose in character and acute to rounded in shape. They are medium to dark green on the upperside and silver or white on the underside of the leaves.
Fuchsia excorticata is one of few deciduous trees in New Zealand. This means they lose their leaves in colder months. Throughout most of its
range in the
South Island and in the mountainous areas of the
North Island,
F. excorticata loses its leaves in autumn and reproduces them in spring, although some populations in the North Island retain them. A population of completely deciduous trees have been recorded as far north as
Auckland. A 1936 study conducted in
Dunedin showed that leaf fall began in early May and lasted for three to four weeks.
F. excorticata remains leafless until new
shoots appear in August or September. Flowering occurs mostly from August to December; flowers grow individually, but the tree can sometimes exhibit
cauliflory, where they grow directly from stems or the main trunk. The
ovaries are 4.5–8 mm long, 1.7–3 mm thick and green in colour. The
sepals are narrow-triangular in character, 8 mm long, 3 mm wide at the base, and lustrous green in colour with dull purple streaks at the upper parts between the ridges, then changing to a red or crimson colour in the middle. The
petals are dark purple in colour and 1.8–5 mm long, 0.7–2.1 mm wide in the middle. The filaments are a purple to pale cream colour, 6–15 mm and 5–10 mm long, pollen-collecting
anthers are also purple, 1.8–2.5 mm long and 1–1.7 mm thick. The
styles are green to yellow in colour and 22–40 mm long. The
stigmas are yellow to green in colour, 1.8–2.2 mm long and 1.4–2.1 mm wide. The colourful blue pollen results from
anthocyanins and
pigments, specifically kaempferol-3-sophoroside and quercetin-3-sophoroside. Fruits are a black to dark purple colour, 9–13 mm long and 5–8 mm thick. The
seeds are a tan colour, 0.75–1 mm long and 0.3–0.6 mm broad, each fruit consists of about 320–670 seeds.
F. excorticata has a gametic
chromosome count of 11. ==Gallery==