Flora of New Zealand Series

Deciduous to evergreen shrubs or small trees, not armed; stems erect, arching, prostrate or decumbent, often tomentose when young. Lvs distributed along stems and often 2-ranked and distichous, or clustered on short shoots, simple, entire or serrulate, usually coriaceous; stipules small, persistent. Fls in small cymes, corymbs or fascicles, rarely solitary, 2-5-merous, pedicellate, moderately small but often showy, ⚥. Hypanthium tubular, closed at apex. Epicalyx 0. Calyx 2-5-merous; sepals short. Petals usually 5, suborbicular to obovate, spreading or erect, white to red. Stamens c. 20. Ovary semi-inferior or inferior, sunken in the hypanthium; carpels 2-5, ventrally free, the walls becoming woody; styles 2-5; ovules 2 per locule. Fr. small and pome-like, globose to turbinate, red, orange, yellow or black, with mealy flesh and 2-5 bony nutlets, with persistent sepals at apex; seeds 1 per nutlet.

SYNOPSIS

Within these sections there are informal aggregations of related spp. to which specimens can usually be referred although precise identification is often very difficult because the taxonomic limits of many spp., as well as their distribution, are poorly known. Some spp. may be apomictic. Although an overall monographic treatment is lacking, useful accounts of the genus are found in Bean, W. J., Trees and Shrubs Hardy in the British Isles 1 ed. 8 (1970), Krüssmann, G., Handbuch der Laubgehölze 1 (1976) and Rehder, A., Manual of Cultivated Trees and Shrubs Hardy in North America ed. 2 (1947). The last work contains one of the very few comprehensive keys to spp. In N.Z. and elsewhere the situation is further complicated by the prevalence of hybrids with their named clones; there are 3 main spp. involved: , and , and forms or hybrids of them are abundant in cultivation throughout N.Z. They are often persistent relics of cultivation in old gardens but are not with certainty known to be truly wild, although a few incomplete specimens possibly represent them. In contrast to the naturalised spp. the lvs are often lanceolate, oblong-lanceolate or narrowly ovate, or if wider, then the plants are usually large deciduous or semi-deciduous shrubs or small trees.

• A. Sect. CHAENOPETALUM. 
• • Petals spreading, suborbicular and white; fr. usually red:
  • conspicuus Marquandfrigidus Wallich2. * glaucophyllushenryanus (C. Schneider) Rehder et E. Wilson3. * lacteus4. * microphyllus* pannosussalicifolius Franchet
• B. Sect. COTONEASTER. 
• • Petals upright and inconspicuous, obovate and often red-tinged, pink or red; fr. red to black:
  • * bullatusdielsianus E. Pritzeldivaricatus Rehder1. * franchetiihorizontalis Decne.5. * simonsiiwardii W. Smith

c. 50 spp., N. temperate Old World regions, especially W. and C. China and Himalaya. Naturalised spp. 7.

Cotoneaster is a genus of great complexity and many spp. are difficult to identify, particularly in the absence of fls and fr. The genus is divided into 2 well marked sections [ see, Flink, K. E. and Hylmö, B., Bot. Not. 119: 445-463 (1966)].