PLAGIANTHUS BETULINQGS, A. Cunningham. 
THE HOUT. | 
OrpER—MALVACE #. 
(Plates CIII. and CIV.) 
PLAGIANTHUS BETULINUS is an attractive tree, from 2oft. to 6oft. high, and is 
widely distributed through the colony, although entirely absent from certain 
districts and extremely local in others. Its habit is remarkably graceful, and in 
general appearance it bears considerable resemblance to the European birch, 
Betula alba, but the leaves are larger. Mr. Traill informs me that it is termed 
‘“houi’’ by the Stewart Island Natives, and by those on the Chatham Islands. 
I believe the same name is applied in other parts of the colony, but learn from 
the Ven. Archdeacon W. L. Williams that it should be termed “ manatu:’’ it 
is the “‘ribbon-wood”’ of the South Island settlers. The trunk is from rft. to, 
rarely, 3ft. in diameter, and is usually clothed with smooth dark-brown bark, 
and crowned with a spreading head, the ultimate branchlets being very slender 
and often pendulous. In the young. state it forms a bush with slender tortuous 
or interlaced branchlets, and distant ovate or rounded leaves variously lobed or 
toothed. In the mature state the leaves are alternate, from lin. to 3in. long, 
and carried on slender leaf-stalks; usually they are broadest just below the 
middle and taper into a long point, the base being wedge-shaped or rounded, 
and the margins are more or less lobed, or cut into teeth, which may be acute 
or obtuse: when first developed they are clothed with short hairs, and furnished 
with a pair of stipules at the base of each leaf-stalk, which, however, quickly fall 
away. 
The flowers are arranged in terminal panicles, sometimes 6in. Jong and 
repeatedly branched: all the flowers may be perfect, or male flowers and perfect 
flowers may be found on the same tree, or even on the same panicle: the 
branches of the panicle are dotted with starry hairs. The flowers are about in. 
in diameter; the calyx is cut into five lobes, alternating with which are five 
small white petals, rounded at the tips; the stamens are about tweive in number, 
and the filaments are coherent below, forming a tube adhcrent with the petals : 
the free portion of the filament is short, and the anther is kidney-shaped. The 
pistil consists of a single carpel with a one-celled ovary having the style included 
in the staminal tube. The fruit is a small dry one-seeded capsule, splitting 
down one side. Owing to the profusion of the anthers the fiowers appear to be 
red, although the petals are white or nearly white. It is usually evergreen, but 
in some localities in the South Island the leaves fall away on the approach of 
_ winter. 
After Cunningham’s description was published it was made the type of 
a new genus, and figured in the ‘‘ Annales des Sciences Naturelles,”’ ser. i1., 8, 
t. 3, under the name of Philippodendron regium, Poit. 
A, Cunningham described one of the forms as a distinct species under the 
name of P. urticinus; but it cannot be separated even as a variety. 
