Aster novi-belgii hybrids
Michaelmas daisy
Perennial herbs with short to long rhizomes; stems erect, terete to slightly ribbed, usually with short simple hairs in lines or stripes above and glabrous below, sometimes completely glabrous, branched only above, (15)-40-150 cm tall. Mid cauline lvs elliptic, oblong, or ovate- to narrow-lanceolate, narrowed or broad at base and slightly auriculate to amplexicaul, entire, or serrulate to coarsely serrate, usually glabrous, sometimes sparsely hairy about margins, 50-100-(170) × 10-30 mm; uppermost lvs smaller, sometimes cuneate, sometimes ± triangular and broad-based. Infl. a few- to many-headed narrow panicle or ± flat-topped cyme. Capitula 25-50 mm diam.; peduncles usually with lines or stripes of simple hairs, sometimes glabrous. Involucral bracts ± equal to very unequal; inner bracts oblong- to linear-lanceolate, acute to acuminate, glabrous, with a diamond-shaped to diffuse green patch near apex and extending down midrib, also sometimes tinged purple, 5-8 mm long; outer bracts green at tip to wholly herbaceous, erect to spreading, and from 2 mm long to = inner bracts. Ray florets numerous; ligules usually violet to blue, rarely white, 7-14 mm long. Ovary with scattered antrorse hairs; mature achenes not seen.
N.; S.: near settlements throughout.
Cultivated hybrid 1958
Waste places, coastal sites, stream banks and swamps.
FL (Dec)-Feb-Apr-(May).
Michaelmas daisies form persistent colonies in many areas where they have escaped or been discarded from cultivation. Many cvs derived from hybrids involving A. novi-belgii L. are commonly grown and a wide range of forms are represented among wild plants. A. novi-belgii sens. strict. is characterised by auriculate cauline lvs, and outer bracts which are equal to the inner, are almost wholly herbaceous, and spreading at the tip. No wild collections clearly show this combination of characters - probably all are of hybrid origin to at least some extent. Most wild plants appear to belong to one of the following 2 hybrid groups, but it is not possible to determine all material.
(1) A. laevis × A. novi-belgii : lvs oblong to elliptic, distinctly auriculate to amplexicaul; involucral bracts unequal, the outer erect and herbaceous only at apex. No N.Z. material has the small, green, diamond-shaped bract apices and very unequal bracts that characterise A. laevis L.
(2) A. lanceolatus × A. novi-belgii : lvs ovate- to narrow-lanceolate, cuneate and somewhat auriculate; involucral bracts subequal to somewhat unequal, the outer erect and herbaceous for about 1/2 length and along midrib. These hybrids differ from A. novi-belgii in the unequal, more membranous, erect outer bracts and the narrower lvs, and from A. lanceolatus in the generally broader, at least somewhat auriculate lvs, and the broader [(1)-1.5-2.5 mm], coloured ligules.
Cvs have also been developed from hybrids between A. novi-belgii and A. dumosus L. which has ± obtuse bracts; these cvs are generally of smaller stature, often < 40 cm, and may occasionally occur wild, but would be difficult to distinguish from depauperate plants of A. laevis × A. novi-belgii.
