Flora of North America species comparison

Species 40–60 (4 in the flora).

Photinia is widely introduced in cultivation and naturalizing, at least in the continental United States. Species are native mostly to warm temperate Asia, from the Himalayas east to Japan and south to India and Thailand. Molecular data suggest that Heteromeles originated through hybridization, with a species of Photinia as pollen parent (Guo W. et al. 2011).

Five species from Mexico and Central America were included within Photinia by J. B. Phipps (1992) and molecular evidence corroborates their placement there (Guo W. et al. 2011).

The Asian Stranvaesia has sometimes been treated as distinct from Photinia, but botanists have noted the apparent artificiality of a primary character used to differentiate the two genera, namely an endocarp dehiscent in Stranvaesia, indehiscent in Photinia (C. Kalkman 1973; J. B. Phipps et al. 1991b; K. R. Robertson et al. 1991; J. R. Rohrer et al. 1991, 1994). Kalkman observed that the putative dehiscence of Stranvaesia carpels is an artifact of specimen preparation. Rohrer et al. (1991, 1994) found that Photinia and Stranvaesia do not differ in connation of the carpels or in the adnation of the carpels to the hypanthium. Molecular phylogenetic analyses (Guo W. et al. 2011) show that the Stranvaesia species have arisen within the cladistic topology of Photinia.

The primarily eastern North American genus Aronia (for example, A. floribunda, A. melanocarpa) has been included in Photinia in some classifications (K. R. Robertson et al. 1991) but is here treated as distinct.

Many species of Photinia are ornamental trees and shrubs with large lustrous leaves and masses of white flowers in the spring followed by red fruits in the fall. The flowers last about two weeks and commonly have an unpleasant smell. The wood is hard and heavy and has been used for furniture and small articles such as axe handles.

Photinias have been widely and abundantly planted for hedging in the southeastern United States. The rapid spread since about the mid 1980s of a fungal leaf spot, Entomosporium maculatum, has been lethal to many such hedges. Photinia ×fraseri ('red tip'; see under 2. P. serratifolia) and P. glabra are severely affected; P. serratifolia is said to be partially resistant.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

As noted by C. Kalkman (1973), Lindley cited Crataegus glabra as a synonym of his proposed new species Photinia serrulata. The concept of P. serrulata by Lindley was not the same as that of C. glabra by Thunberg, and P. serrulata Lindley has persisted as a name in use for P. serratifolia. In any case, the publication of P. serrulata was superfluous and illegitimate.

Photinia ×fraseri Dress, or 'red tip,' is a popular hybrid cultivar between P. glabra and P. serrulata, valued especially for its brilliant burgundy red young leaves, which mature to green over weeks through shades of copper red. Shrubs are 3–4(–4.5) m; leaf blades elliptic to oblong-obovate or elliptic-obovate, 7–12 × 3–4(–4.5) cm, basally cuneate, with petioles 1–1.5(–2.3) cm. The leaves are smaller than those of P. serratifolia but tend to be longer and slightly narrower, with sharper teeth, than those of P. glabra. Apparently, fruit set is very low and the plants have not been recorded as escaping cultivation. In Texas, P. ×fraseri produces an abundant flush of new leaves in late October through November, when neither of the parents is doing so.

(Discussion copyrighted by Flora of North America; reprinted with permission.)