Deconfusing Plumeria

Plumeria  is a genus of flowering plants in the dogbane family, Apocynaceae. Most species are deciduous shrubs or small trees.

The species variously are indigenous to South and Central America, but are grown as cosmopolitan ornamentals in warm regions.

Etymology

The genus is named in honor of the 17^th century French botanist Charles Plumier, who traveled to the New World documenting many plant and animal species.

The common name "frangipani" comes from a 16^th century marquis of the noble family in Italy who claimed to invent a plumeria-scented perfume, but in reality made a synthetic perfume that was said at the time to resemble the odor of the recently discovered flowers.

Botanical Description

branches widely spaced, thick succulent, brittle, thin grey bark, milky latex. 

Leaves are simple, whorl at tip of branches.

Flowers are fragrant, radial symmetry ( actinomorphic ), cymes, perfect, 5-lobed calyx. 5 petals.

Fruits are follicles, 2-horned, cylindrical, split when mature. 

Seeds winged, 20-60 within a fruit.

Plumeria rubra : Forms & Sizes

The estimated number of Plumeria species ranges from five (Wiersema, 2008) to 45 (Llamas, 2003).

In 1938, R.E. Woodson organized P. rubra into four forms delineated by the primary colors of the flowers: white, yellow, pink, and a tricolor.  Today, many hundreds of variations of these four forms exist.

Hortus Third (Bailey and Baley, 2000), recognized the four forms of P. rubra as described by Woodson.

Plumeria rubra f. acutifolia has white flowers with yellow centers.

Plumeria rubra f. lutea has yellow flowers fading to white at the edge as they mature.

Plumeria rubra f. rubra has pink flowers of varying intensity with a tangerine-yellow center.

Plumeria rubra f. tricolor has pale yellow-white flowers with tangerine-yellow centers and red or pink rim.

Source : Stephen H. Brown, Identification of the Four Forms of Plumeria rubra, Proc. Fla. State Hort. Soc. 121:406–407. 2008.