Populus yunnanensis Dode
Yunnan poplar
Large, widespreading tree, suckering moderately. Bark grey, fissured. Shoots ± angled when young, almost winged in strong vegetative shoots, reddish purple to yellowish brown. Buds very viscid, glabrous. Young shoots strongly viscid and balsam-scented. Petiole to c. 10 cm long, nearly terete, glabrous. Lamina to 18 × 13.5 cm, broad-ovate, glabrous except for minutely ciliolate margin, greenish white below, glossy green above, reddish brown when unfolding; midrib and veins pink above; margin crenate-serrulate, without translucent band; base subcordate to cordate, glandless; apex acuminate. Catkins ♂, pendulous, to 16 cm long. Bracts 2-4 mm long excluding long filiform teeth, glabrous, whitish. Rachis glabrous. Cup-shaped disc 1-3 mm deep, oblique, glabrous. Stamens 15-45; anthers crimson towards apex.
N.: Auckland; S.: Christchurch.
S.W. China 1988
Riverbanks.
FL Sep-early Oct.
Yunnan poplar has been very commonly planted in many places since its introduction in the 1930's; now it is not always possible to ascertain whether trees along riverbanks or near shelter belts were originally planted. It is apparently the most likely balsam poplar to grow wild in many areas, although it does not sucker as extensively as P. × gileadensis.
P. yunnanensis has spontaneously hybridised with P. deltoides `Virginiana' at Waipukerau and Waitotara in the North Id.
P. yunnanensis, as found in N.Z., is distinguished from the other 2 balsam poplars described here by the pink lf veins and very glossy upper lf surface. Another feature of this sp. in N.Z. is that until recently all the trees were ♂ (probably from a single clone), but ♀ clones have now been introduced to cultivation.
