Helianthus ×laetiflorus Pers.
perennial sunflower
c. 1.5 m tall, dying back in winter. Lower and mid cauline lvs hispidulous, shortly petiolate or apetiolate, narrow-ovate to narrowly ovate-elliptic, acute to acuminate, long-cuneate at base, serrate, (4)-8-25 cm long; upper cauline lvs similar to lower but uppermost sometimes alternate, smaller, narrower and apetiolate. Capitula 5-10 cm diam., in loose corymbs of 1-7. Involucral bracts in 2-3 rows, ciliate, otherwise glabrous or sparsely hairy, ovate-triangular or outermost lanceolate, acute to acuminate, 6-12 × 2-4-(5) mm. Receptacle convex; scales membranous, the larger with darker ciliate apices. Ray florets c. 20-30; disc florets numerous, usually yellow, sometimes reddish brown. Achenes not seen.
N.: Auckland City, Te Rore (Te Awamutu District); S.: vicinity of Christchurch, and Ashley R. (near Rangiora, Canterbury).
U.S.A. 1968
Waste places.
FL Feb-Mar.
Erect perennial herb, with rhizomes and sometimes small, poorly developed tubers. Stems scabrid, not branched or much-branched above at flowering, up to
H. × laetiflorus is cultivated for its showy fls, but is now grown less often than formerly. It has established locally in the wild, probably as a garden discard, and forms small colonies from the rhizomes; it does not appear to produce mature achenes. Plants grouped under this name are thought to be hybrids between the N. American H. rigidus (Cass.) Desf. and H. tuberosus. The rhizomes usually lack the tubers characteristic of H. tuberosus, but these may be weakly developed in some colonies. H. × laetiflorus is also distinguished from H. tuberosus by the ovate-triangular involucral bracts (Fig. 24). It has been previously recorded in N.Z. as H. laetiflorus.
