Trifoliate orange; Hardy Orange ‘Flying Dragon’ (poncirus trifoliata)

‘Flying Dragon’ is distinguished from the ordinary Poncirus Trifoliata, by spines which curve strongly backward, in claw-like fashion. This interesting, ornamental growth habit is particularly evident when the plant is leafless. Highly prized in the Orient, where it has been cultivated for centuries. ‘Flying Dragon’ is also a dwarf, growing to a maximum height of 6′ (smaller in containers). Commercially used as a dwarfing rootstock for citrus. Should be a good candidate for bonsai training.

The ordinary Poncirus Trifoliata is a small, very spiny tree, of interest in being a hardy, deciduous near-relative of citrus fruits. Because the twigs and spines are green, the plant appears green even when it is leafless. Produces attractive, supposedly fragrant, white flowers in spring, which develop by fall into yellow fruits resembling small oranges. These sour, fruits are often considered inedible. Michael Dirr, in his Manual of Woody Landscape Plants, however, comments that “Ripe fruits set aside for several weeks become juicy and develop a sprightly, slightly acid flavor. Serves as a substitute for lemon, pulp can be made into marmalade, and peel can be candied. After removing the numerous seeds there is not a whole lot of pulp left over.” Used commercially as a rootstock on which to graft other citrus fruits. Considered cold hardy to about -15° F, its range of cultivation can be extended into zone 5 if it is planted in a sheltered location and perhaps given some extra protection.