1938

monograph on plumeria species (Robert Woodson, 1938) subsumes many Caribbean plumeria species names under Plumeria obtusa. A form found in the Bahamas was called P. bahamensis, but it was subsumed under P. obtusa by Woodson. One online reference I found listed some 60 species names that had been subsumed under P. obtusa. Since that monograph was developed from herbarium sheets rather than live material, I think there are some species names that should be resurrected, but it will take DNA surveys to resolve this. In the monograph, there is a variety or subspecies of P. obtusa that has been going by the name Tuberculata because of the raised leaf attachment points after the leaves abscise. This is correctly, Plumeria obtusa var. sericifolia, but the underside of the foliage has fine silky hairs and very raised veins. Whether it is truly a variety of P. obtusa remains to be determined as there are several characters that suggest it may be a separate species of its own. A number of collectors are using old species names without any published support from taxonomists. Richard Eggenberger lists several forms of P. obtusa in his book, The Handbook on Plumeria Culture. Here in Hawaii, the P. obtusa does not set seedpods with any sort of frequency. I had a rare seed pod several years ago and the seedlings gave rise to both P. rubra and P. obtusa type foliages. I am guessing that the Australian P. obtusa is likewise a hybrid that has been widely distributed by vegetative means, but it appears to set seed and the progeny have P. rubra characters. Jim Little brought back a P. obtusa from Hong Kong a number of years ago. It tends to be a more "squatty" form, also not seedpod productive. Both the Hong Kong and Hawaii forms have large flowers with broad petals. Nong Nooch Tropical Garden (Thailand) gave us a P. obtusa var. obtusa that has "typical" leathery, blunt-tipped foliage and small white fragrant flowers. It is difficult to know if this is the same one referred to by Eggenberger. Obtusas are the most drought tolerant of all plumerias, which also means they hate mix compaction the most. You want to make sure you have really good drainage in your containers. Singapores do lose leaves, just not in winter. Begins to shed the oldest leaves about the same time that the first new leaves have formed in late spring or early summer. Old leaves rotate out as more new leaves form. Unless you are leaving the plant out in very cold weather, there are always some leaves on the branches. Sets seed, but very difficult to germinate and grow.