Spiraea japonica L.f.
(W.R.S., D.R.G.)
Semi-deciduous shrub up to c. 1.5 m high, forming small thickets; stems ± erect, stiff; young stems finely striated, pilose, reddish; bark of older stems reddish and smooth. Lvs spreading or slightly ascending; petiole 3-5 mm long, narrowly winged, sparsely pilose, ± reddish, channelled above; blade lanceolate to narrow-ovate or narrow-elliptic, 40-100-(110) × 10-30-(35) mm, acuminate, cuneate at base, glabrous except for principal veins and margins near petiole when young, with network of veins showing distinctly on glaucous to pale green underside of blade, regularly or somewhat irregularly and rather shallowly 2-serrate. Infls densely hairy or tomentose, spreading, compound corymbs terminating short branches, up to 100 mm wide and 40 mm long; peduncles 3-5 mm long, slender. Sepals triangular, 1-1.5 mm long, hairy, sometimes densely so, dark green and sometimes magenta-tipped. Petals broadly ovate to orbicular, c. 2 mm diam., rose-red. Stamens c. = petals. Fr. of diverging, brown, glabrous follicles.
S.: Westland (Whataroa, Potters Creek to Tatare Stream, and Okarito Forks).
Japan, China 1975
Roadsides and partly shaded waste places up to c. 100 m.
FL Nov-Mar.
S. japonica is widely cultivated as an ornamental shrub in N.Z. and is represented by a number of cvs. The plant described above is sometimes known as Spiraea `Bumalda', and Bean, W. J., Trees and Shrubs Hardy in the British Isles 4 ed. 8 (Clarke, D. L., Ed., 1980), treated this as a cv. of unknown origin under S. japonica. At least some of the S. japonica seen in gardens is probably `Anthony Waterer' which, according to Bean, originated as a branch-sport on cv. 'Bumalda'. `Anthony Waterer' seems to have fls of a deeper colour than the wild plants in N.Z.
