Vitex agnus-castus, also called vitex, chaste tree, chasteberry, Abraham's balm, lilac chastetree, or monk's pepper, is a native of the Mediterranean region.
 It is one of the few temperate-zone species of "Vitex", which is on the whole a genus of tropical and sub-tropical flowering plants. Theophrastus mentioned the shrub several times, as "agnos" (άγνος) in "Enquiry into Plants".
 It has been long believed to be an anaphrodisiac but its effectiveness remains controversial.
 This is a cross-pollinating plant.
 However self-pollination may also occur now and then.
Gynura aurantiaca, called purple passion or velvet plant is a species of plants in the chrysanthemum family It is native to Southeast Asia but grown in many other places as a house plant.
 In warm regions, it is frequently grown in outdoor on patios and in gardens rather than inside buildings, and hence it has escaped into the wild in Africa, Australia, South America, Mesoamerica, Florida, and a few other places.
Simarouba glauca is a species of flowering tree that is native to Florida in the United States, southern Florida, South America, and the Lesser Antilles.
 Common names include paradise-tree, dysentery-bark, and bitterwood.
 Its seeds produce an edible oil.
 The tree is well suited for warm, humid, tropical regions.
 Its cultivation depends on rainfall distribution, water holding capacity of the soil and sub-soil moisture.
 It is suited for temperature range of 10 to .
 It can grow at elevations from sea level to 1000 m .
 It grows 40 to tall and has a span of 25 to .
 It bears yellow flowers and oval elongated purple colored fleshy fruits.
Plumeria rubra is a deciduous plant species belonging to the genus "Plumeria".
 Originally native to Mexico, Central America, Colombia and Venezuela, it has been widely cultivated in subtropical and tropical climates worldwide and is a popular garden and park plant, as well as being used in temples and cemeteries.
 It grows as a spreading tree to 7 – high and wide, and is flushed with fragrant flowers of shades of pink, white and yellow over the summer and autumn.
 Its common names include frangipani, red paucipan, red-jasmine, red frangipani, common frangipani, temple tree, or simply plumeria.
Vitex is a genus of flowering plants in the family Lamiaceae.
 It has about 250 species.
 Common names include "chastetree", traditionally referring to "V. agnus-castus" but often applied to other species as well.
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 Mexico, Polynesia, Central America, and the Caribbean, and as far south as Brazil, but are grown as cosmopolitan ornamentals in warm regions.
 Common names for plants in the genus vary widely according to region, variety, and whim, but frangipani or variations on that theme are the most common.
 Plumeria also is used directly as a common name, especially in horticultural circles.
Kuding or ku ding (; pronounced ) is a particularly bitter-tasting Chinese infusion, which due to their similarities in appearance is derived from several plant species.
 Two most common plants used to make kuding, being the wax tree species "Ligustrum robustum" and the holly species "Ilex kaushue" (synonyms: "Ilex kudingcha") plant, the former being more commonly grown in Sichuan and Japan while the latter is most commonly grown and used in the rest of China.
 This type of tea may be caffeinated if from the "Ilex" genus, but is caffeine-free if from the Ligustrum genus.
Plumeria obtusa, the Singapore graveyard flower, is a species of the genus "Plumeria" (Apocynaceae).
 It is native to the West Indies including Bahamas; southern Mexico, Belize, Guatemala, and Florida.
 but widely cultivated for its ornamental and fragrant flowers around the world, where suitably warm climate exists.
 It is reportedly naturalized in China.
Vitex negundo, commonly known as the Chinese chastetree, five-leaved chaste tree, or horseshoe vitex, is a large aromatic shrub with quadrangular, densely whitish, tomentose branchlets.
 It is widely used in folk medicine, particularly in South and Southeast Asia.
Aeschynomene is a genus of flowering plants in the family Fabaceae, and was recently assigned to the informal monophyletic "Dalbergia" clade of the Dalbergieae.
 They are known commonly as jointvetches.
 These legumes are most common in warm regions and many species are aquatic.
 The genus as currently circumscribed is paraphyletic and it has been suggested that the subgenus "Ochopodium" be elevated to a new genus within the Dalbergieae, though other changes will also be required to render the genus monophyletic.

Question: Which flowering tree genus is commonly grown as ornamentals in warm regions, Plumeria or Vitex?
Answer: Plumeria