The flower panicles of C. banksii are longer and
looser than those of C. australis at least a metre long, and arch
out and down among the leaves. The flowers are fewer and longer
than those of C. australis, and with the same sort of sweet fragrance.
In much of the top half of New Zealand's North Island, at least,
C. banksii is a rather straggly and sparse little thing, with a
few long narrow leaves on a slender stem that quite often leans
one way. The upper end of the Kauaeranga Valley at the base of the
Coromandel Peninsula has its own, more impressive form however,
which has blades up to 10 or 11cm wide. Here, C. australis is exclusively
a coastal and lowland species, while C. banksii ranges from the
foothills to just below the peaks of the Coromandel Ranges, to 930m.
Also unlike the other New Zealand species, C. banksii has a wide
light level tolerance, and can be found fully under the shade of
Leptospermum trees, or in full sun in waist-high subalpine scrub.
A common place to find it is leaning out from steep rocky banks
where roads and tracks cut though hilly bush; here all the leaves
swing round and hang the same way, out to the sun.
The trunk habit varies drastically with the position
the plants are growing in, as well as from genetic influences. The
plants in the top photo have single 5m trunks. Some others are multi-stemmed
from the base. Some stay unbranched while flowering, but most branch,
particularly in full sun. At the highest altitudes on the mountains
fringing the Kauaeranga valley they are nearly stemless, resembling
the Phormium cookianum they grow in association with there.