Flora of New Zealand Series

tauhinu

Shrub < 0.5-5 m tall. Stems densely tomentose and sometimes glandular, but without long straight hairs. Lvs from almost glabrous to moderately clothed in white tomentum on upper surface, with dense white tomentum on lower surface and sometimes with sparse to dense covering of glandular hairs giving a yellow appearance to lf, apetiolate, usually oblong to narrow-obovate or elliptic, rarely linear or ± obtriangular, slightly revolute but lower surface not greatly obscured, 1.5-10-(15) × 1-3-(4) mm. Capitula in small, dense, rounded corymbs. Involucral bracts sparsely to moderately hairy especially on stereome of outer bracts, 1-4 mm long, mostly translucent, sometimes tinged pink or red in bud, often the inner bracts with milky white radiating lamina. Florets 4-15-(25) per capitulum; receptacular scales few to many or 0, with white radiating lamina slightly exceeding corollas. Achenes glabrous or with scattered antrorse hairs, square in section and slightly narrowed to base, 1-1.7 mm long; pappus denticulate, scarcely to distinctly thickened at apex.

N.; S.; St.; A.

Endemic.

Coastal dunes and lowland to subalpine scrubland and grassland.

FL (Aug)-Nov-Feb-(Mar).

Allan (1961 accepted 5 spp. and several vars for N.Z. Cassinia and even more names have been based on N.Z. plants. C. leptophylla displays considerable local differentiation but there are no characters which clearly delimit more than one spp.; characters used previously, e.g. lf shape and size, and number of receptacular scales, often vary continuously among or even within populations. Previously-used characters tend to vary independently of each other so that many plants are not clearly referable to any of the previously accepted spp. All forms have a dense white tomentum on the young stems and on the lower surface of the lvs; this sometimes extends to the upper lf surface. The white tomentum is often overlain with yellowish glands, and it is the density of these glands which determines the colour and stickiness of lvs and stems. All degrees of gland density are found among populations of lowland and subalpine plants, and plants with white or yellow tomentum may be found in otherwise ± uniform populations [ see, Wilson, H. D., Wild Plants of Mount Cook National Park (1978)]. Plants with narrower lvs and yellow tomentum are often referred to C. fulvida Hook. f. In the South Id and lower North Id plants from higher altitudes generally have thick twigs (2-2.5 mm diam. below lvs), large lvs (c. 4-7 × 1.5-3 mm), more often have a yellow tomentum and sometimes have the bracts tinged pink in bud; plants from lower altitudes often have thin twigs (1-1.5 mm diam. below lvs), small lvs (c. 1.5-3 × 1-1.5 mm), and more often have a white tomentum. Lowland plants are often referred to C. leptophylla and upland plants to C. vauvilliersii (Decne.) Hook. f., but there is no clear discontinuity between these forms. Similarly C. retorta DC., described from the northern North Id cannot be clearly distinguished from C. leptophylla. Distinctive local populations may be defined by combinations of characters, as with plants described as C. amoena Cheeseman, but these do not merit recognition at sp. rank. The division of C. leptophylla into subspp. or vars is probably warranted, but a satisfactory treatment must await a more detailed analysis of this variable sp. The common names cottonwood, golden tauhinu, dune tauhinu and mountain tauhinu are used.