Scientific Name:
Pyracantha M.Roem., Fam. Nat. Syn. Monogr. 104, 219-220 (1847)
Vernacular Name(s):

Evergreen shrubs, usually armed with spines;  stems usually rigid and spreading, sometimes sprawling, sometimes tomentose when young.  Lvs alternate and spaced on young vegetative shoots, otherwise in fascicles along older stems, simple, usually serrate or crenulate, sometimes entire, ± coriaceous;  stipules minute, deciduous.  Infl. a compound, often ± flattened corymb.  Fls 5-merous, ☿, pedicellate, moderately small.  Hypanthium tubular, closed at apex.  Epicalyx 0.  Sepals short, connate at base.  Petals suborbicular, spreading, white.  Stamens 20.  Ovary ± inferior;  carpels 5, free on ventral side;  styles 5; ovules 2 in each locule.  Fr. small and pome-like, red, yellow or orange, with mealy flesh and persistent calyx;  carpel walls woody;  seeds 5.

[From:  Webb et al. (1988) Flora of New Zealand. Volume 4.]

Number of species in New Zealand within Pyracantha M.Roem.
Exotic: Fully Naturalised3
Mabberley, D.J. 2008: Mabberley's plant book, a portable dictionary of plants, their classification and uses. Edition 3. Cambridge University Press.
Roemer, M.J. 1847: Familiarum Naturalium Regni Vegetabilis Monographicae . Vol. 3. Landes-Industrie-Comptoir, Weimar.