The Handbook on Plumeria

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Description

PLANT TYPES AND STRUCTURE

Plumerias range in size from dwarf shrubs that even in the most ideal climates rarely grow more than 3 to 4 feet in height after many years, to large trees that may attain heights up to 40 feet with an equally impressive spread. Plumeria obtusa and its varieties are primarily evergreen while most of the other species are briefly deciduous in their native habitats.

In the more desirable species and cultivars, growth habit is compact with multiple branching and dense foliage in whorls at the ends of the branches, and crowned by large inflorescences. Immature branches are green and soft, almost succulent, shiny, and in some varieties lightly pubescent. Mature wood is gray and characterized by prominent leaf scars. In some species the leaf scars are so prominent that the bark appears warty. In most species and hybrids the bark is smooth and though it is occasionally thick, cork-like and furrowed, leaf scars are always evident to some degree. Branches have some elasticity but in young plants will not sustain weight and break easily. Mature trees develop much greater strength and it is possible to climb near the top of 30 foot specimens without breaking a limb.

As to the structure of the plants, we have come across some rather unique descriptions. Cowen writes: "Although rarely without flowers, it is leafless from December until the rains and, beautiful though the flowers may be, they cannot conceal the ugliness of the pale swollen limbs."

Here is a description by Menninger from his Flowering Trees of the World: "... 'an awkward set of wooden antlers topped with nosegays. The gouty, soft-barked trunk and the gray, non-tapering branches that are more conspicuous than the foliage, fake it the ugly duckling of the tropical garden. It is saved from oblivion only by the requisite and often heavy fragrance of its waxy flowers which rival both the Jasmines and the Gardenias."

From Firminger's Manual of Gardening for India: "... not ill-looking when in full foliage, with its large, lanceolate, smooth leaves, nine inches long and two and a half wide, borne, crowdedly, towards the summits of the stems, but remarkably uncouth ^hen the succulent, gouty-looking stems are destitute of leaves, as they often are in he cold months."

In Some Beautiful Indian Trees, Blatter and Millard write: "In full leaf the tree is not without elegance, but stripped of its handsome foliage, its crooked trunk and the

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grotesque outlines of its blunt and swollen branches give it an uncouth and gouty appearance."

Colthurst, however, in Familiar Flowering Trees in India, achieves a balance,  seeing beauty evolve from the beast:

It is a small, gouty-looking tree, which is often leafless but rarely out of bloom, with thick, smooth branches that do not taper at all, and are full of a tenacious white milk.

For all its fragrance, the Frangipani are not exactly what one would call artistic trees, and time was when I vigorously excluded it from my garden, but one day I came upon Waterfield's eulogy of it in his "Ballads" [See Religious and Cultural Symbolism], and now, for the very beauty of his ideas and the music of the poem it is one of my favorites.

In The Modern Tropical Garden, Kuck and Tongg also write in a more positive tone: "One of the most popular and attractive of smaller flowering trees with picturesque form and flowers useful for many purposes. . . . Flowers which appear on the bare tree, in large clusters near branch ends, create a particularly picturesque effect. '

As we can see from the above, no botanist, horticulturist or tropical plant enthusiast who has written anything descriptive about plumerias has minced words when giving a detailed account of the rather awkward, ungainly form of the plant with its swollen looking branches, greyish scarred bark and angular branching structure. All are equally unanimous, however, in their appreciation of the abundant and of en spectacular bouquets of fragrant flowers that cover the plant for many months of' he year. The plumeria does have its champions and a few even see beauty in the form,   which can be highly architectural with its bold sculptured lines and forked branches supporting tufts of leaves above which are held the magnificent clusters of perfumed flowers.

Taylor writes in his Encyclopedia of Gardening: ". . . very handsome shrubs and trees . . .", and T.M. Greensill in Tropical Gardening makes a fine statement: "Generally, this small tree is not given the attention it deserves. A well-tended specimen has branches about a foot from the ground and is perfectly symmetrical in shape, with the lower leaves almost sweeping the ground. ... A well-shaped specimen is one. of the most beautiful sights in the tropics...."

GROWTH HABITS AND LIFESPAN

With the exception of the dwarf varieties most plumerias grow rapidly, easily attaining 2 to 3 feet a year in tropical areas under favorable conditions. In the south

ern and western states, plants often grow at least 1 foot per year with good culture Though some seedlings and uncultivated varieties exhibit undesirable characteristics such as tall spindly growth with sparse branching and inflorescences so high one needs a ladder to appreciate the flowers, in better varieties branching occurs at close intervals and growth is symmetrical. During the development of an inflorescence the tip of a branch, latent buds immediately beneath will begin to initiate growth ;

branches will emerge and continue to grow throughout the flowering period. In some

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varieties only 1 or 2 branches are typical, but in more vigorous types at least 3 or even many as 5 or 7 will develop. Each new branch leads to a potential inflorescence in he next 1 to 2 years. Plumerias are very long-lived plants. The original Plumeria rubra forma acutifolia introduced by Hildebrand to the Foster Botanic Gardens still grows where it was planted 128 years ago. Even older specimens are reported to be alive and flowering in Mexico

.

LEAVES

Plumeria leaves are arranged alternately and are crowded near the ends of the branches. The leaves of different species and hybrids exhibit considerable variation (see Appendix A) in shape, size, color and density. In general, leaves are thick, stiff, leathery and light to dark green in color with a well developed mid-rib and a distinct intramarginal vein that connects the prominent lateral, feather-like veins that run at right angles to the mid-rib. The leaves of Plumeria obtusa, for example, are a rich dark green, obovate to obovate-oblong, with rounded tips and thick mid-rib and lateral veins. Leaf sizes range from 5 inches in length to some we have measured at more than 20 inches and vary from ^1/2 inch across to nearly 6^1/2 inches at the widest point. Most species and hybrids are glabrous but a few are moderately pubescent.

INFLORESCENCE

Flowers are produced on terminal thyrsiform inflorescences that usually rise well above the foliage providing a mass display that is incomparable. A few species and sub-species produce their inflorescences among the leaves and one, P. caracasana (specific epithet doubtful) bears huge clusters beneath the foliage. Some inflorescences, such as those of cultivar 'Japanese Lantern', are initially upright and become pendulous as they mature. We have often observed inflorescences with 20 to 30 flowers open at one time on plants grown in the ground under good cultural conditions. Yet, many of today's modern hybrids will produce almost the same number of blooms on container grown plants only 2 to 3 years old!

FLOWER SHAPES, SIZES AND COLORS

Flowers are generally medium to large though there are small flowered species and Vends. The corolla is salverform with 5 lobes convolute in bud and a slender corolla tube. Stamens and other reproductive parts are not visible, being inserted deep within the  corolla tube. There are 5 stamens borne on the corolla, the anthers separate and free from the short 2-lobed stigma, pistil with 2 half-inferior ovaries and a single, spindle-shaped style. Flowers are usually very showy and fragrant, in a range of hues with white, pink, yellow and red the representative colors, although many new hybrids have beautiful orange, golden and salmon shades with a few hybrids definitely tending toward lavender. There is often a deeper band of red, rose-pink or pink

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on the reverse outer edge of the petals. The inner margin of the lobe curls inward, We have observed variations in the number of lobes from 3 to 7, with a few hybrids displaying 6 lobes on 50% of the blossoms.

Individual blossoms are most often 2 to 4V2 inches across in hybrid forms, v. [A some varieties approaching 6 inches. Shapes range from large star-shaped blossom, with very narrow, widely separated petals to tightly overlapped, saucer-shaped forms and every conceivable variation in between. Some flowers have a pinwheel shape with the corolla lobes pointed and reflexed while others have rounded lobes. In other hybrids the corolla lobes may be twisted or undulate (see Appendix A).

Flower color may vary according to the conditions under which a plant is grown. We have observed flowers shading to lavender rather than pink when grown under fiberglass. Plants flowered in too much shade will also be far from their true color. Flowers on immature plants such as second or third year seedlings as well as first year cuttings may not be true to color or size.

FLOWERING SEASON AND HABIT

In Hawaii the heaviest flowering season extends from April through October. In Southern California plants bloom from June through November (nearly that Ion.;; in the southern and southeastern states) and occasionally into December. In most of the tropics P. obtusa is almost perpetually in bloom. Flowering habit varies greatly according to climate and habitat. Menninger writes: "In Florida the trees are leafless in spring when flowering begins and the flowering may continue for months. New leaves gradually appear as the blossoms drop away." T.H. Everett in the New York Boanical Garden Encyclopedia of Horticulture writes: "In climates with a definite dry sea- son they usually flower when they are leafless, but in constantly moist climates they are likely to be evergreen and bear flowers and foliage at the same time." In Flowering Trees of Guatemala, Chickering observes: "The traveler who passes through the Motagua Valley during the spring or early summer will see, rising among the dry shrubs and cactus along the roadside or the railway, occasional small trees surmounted by large clusters of glistening white flowers. Early in the season the trees are often leafless. . . ." In India mature trees of P. rubra forma acutifolia begin to drop their leaves with the onset of the heavy rains, remaining leafless for 6 to 8 weeks. The period of heaviest bloom is January and February, in a leafless condition, and in March when the new leaves burst forth.

Steiner writes that the 'Red Kalachuchi' {Plumeria rubra), blooms from February" to November in the Philippines while the 'White Kalachuchi' (Plumeria obtusa), bloorns throughout the year. O'Gorman writes, referring to P. rubra forma acutifolia in Mexico: "The leaves . . . usually do not appear until after the blossoms in spring." she continues: "In Acapulco many of the white flowered species grow in the surrounding hills. Here, as in the tropical zone of Papantla, the flowers appear together with the foliage and not on bare branches, and the blossoms can be seen as late as July."

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FRAGRANCES

The plumeria is synonymous with perfume. According to Woodson, Jacquin described the odor as ". . . perhaps the sweetest of any plant living,. . . ." "Only the bloom of the jasmine with which it is so often identified can compete in sweetness and penetration of scent." (Flowering Trees of the Caribbean). Miller and Hubbard write The Standard Cyclopedia of Horticulture: "Plumerias are among the most fragrant of  tropical flowers, vying in this respect with the jessamine, Cape jasmine and

tuberose."

Plumeria flowers are most strongly scented during the evening and in the morning and fragrance is faintest during the heat of mid-day. Fragrance in plumerias is a study unto itself and should be thoroughly researched. No other flower seems to be possessed of so many different and intoxicating perfumes. Though one occasionally finds a flower that is odorless or only mildly scented, most plumerias have strong and wonderful fragrances, variously described as citrus, coconut, rose, cinnamon, honeysuckle, jasmine, gardenia, lemon, fresh peaches and other aromatic fruits. The Frangipani fragrance is associated only with the widely cultivated species, Plumeria rubra forma, acutifolia, a medium size white flower with a prominent yellow center.

Overall, as a group, the plumerias we grew in India seemed to be the most highly scented, often exquisitely so. We noticed this same phenomenon with oleanders as well. Whether this was due to the type of soil, the sun, water, fertilizing or other unknown factors, we do not know. In Auroville we conducted an interesting experiment with a group of school children ages 4 to 13 who came weekly to the Matrimandir Gardens to study plants and Nature. We evolved a game of identifying flowers while blindfolded, by their scent alone. The children took this challenge quite seriously and were delighted when they learned to identify many different flowers by their characteristic fragrance. After a time they were able to distinguish at least twelve distinct plumeria fragrances.

Each time we visit Hawaii, or perfumeries in other places, we always hope we will find a plumeria perfume that truly captures the essence of the plumeria fragrance. There are numerous companies producing 'Plumeria' perfumes, but to date we have been disappointed in the results. Senor Frangipani must have found the secret and kept it closely guarded.

FOLLICLES AND SEEDS

Seed pods, or follicles, are produced in abundance in some species and many Vends and take about 8 months to mature. Follicles are usually stout and appear in Pairs (typical of the Apocynaceae family) though occasionally only one will form. They  are easily noticeable on the trees, are of smooth texture and brown to reddishbrown  in color. For more information on seeds refer to the chapter on Propagation.

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