Australasia will be our first stop on this virtual visit. Mind you, I am not taking you on an Australian or Papua tour but this is where Tristellateia australasiae comes from. A member of the Malpighiaceae family, the genus Tristellateia groups some 20 species of woody climbers which has a large area of origin, including Madagascar, southeast Asia, New Guinea, Australia as well as one species from Africa and one from New-Caledonia (another overseas French territory like Reunion, but off the east coast of Australia). Tristellateia australasiae can be found growing wild from southeast Asia to Australia, including Taiwan, Malaysia and New Guinea. It can reach 10 meters (30 feet) in height. The leaves are simple, shiny dark green; the flowers are bright yellow, with five petals and produced most of the time in tropical locations, preferably in full sun, they come in erect short clusters. As it can withstand sea salt, it will do all right even if grown near the ocean.
We will stay in the east and hop onto India now as the next plant carries the name of Thunbergia mysorensis, hence revealing its provenance as Mysore in southern India. Thunbergia includes some 90 species of vines and shrubs mostly from Africa and India, one of the 256 genera of the rather large Acanthaceae family. Another woody climber, this one will grow up to 6 meters (20 feet) or more and can cover a tree pretty fast. Leaves are narrow and shiny green. The flowers are particularly showy as they come in long pendulous clusters up to 30 cm (1 foot) long; each individual flower has a hood shape, dark red on the outside and yellow inside, with large erect stamens. Those flowers act as receptacles for rain which then mixes with nectar and pollen to produce a sweet drink that is very attractive to small birds and butterflies. The plant is easy to grow, enjoying full sun to partly shaded places in any well drained soil. Propagation is also quite easy through cuttings.
Now we take a giant leap over oceans and continents, all the way to Latin America, where our third plant for today comes from. Another showy species but which should not be grown if you are in a tropical location as it will soon escape and become a real threat to other plants including large trees. As a matter of fact it is even prohibited in southern Florida and in several places worldwide. Not surprisingly it belongs to the Convolvulaceae family and therefore a close relative to morning glories though not an Ipomoea. This one, Merremia tuberosa, is also a twining vine but it becomes woody and can grow to 30 meters (100 feet) tall or even more, so it is a serious danger for even tall trees. It has handsome palmate leaves, usually bearing seven lobes, and bright yellow flowers which have the usual trumpet shape of most plants of the family. The vine is famous for its dry fruits which give it its familiar name of "wood-rose." The bracts and papery capsule surround the large black seeds and are highly decorative and surprisingly strong. As a seed gatherer I sometimes harvest those ‘roses de bois' and pack them in large cardboard boxes for customers in Europe and they most usually travel without damage. Merremia tuberosa is found in many parts of Reunion and can overtake almost anything from trees to abandoned houses in a short time.
After such a giant leap we will stay in Latin America for the next two vines we will study. South and Central America are home for 95 percent of passion flowers, the remainder being found in Asia, Australia and North America. This large family of plants includes approximately 500 species divided into some 18 genera. Passiflora miniata, the ‘red passion-flower' has been called and sold under the wrong name of Passiflora coccinea for many years and is still often misnamed in many books and mislabeled in nurseries. Anyway it is indeed a very decorative one with its bright red flowers which can be 10 cm (4 inches) wide, both sepals and petals are scarlet or red. The corona filaments are on three ranks with the outer one deep purple and the inner ones white. Leaves are oblong and entire, nothing special about them. Fruits looks just like a small watermelon, spherical with mottled green exocarp ripening light orange, the flesh is perfectly edible and the fruits can be found on street markets in Brazil where they are called ‘thome assu'. Propagation is done by seedling or cuttings and the plant will grow in loose to sandy soil, in full sun. It does not tend to run in the wild and become aggressive like several other passion plants and can be grown even in tropical areas without problems. It closely resembles P. vitifolia but this one produces three-lobed leaves and its outer corona filaments are the same color as the petals while the fruit is ovoid.
As already stated we will remain in Latin America but will move from one plant family to another one, the Bignonaceae. Another pretty big family with some 110 genera of trees, shrubs, climbers--some of which are very well-known, like Jacaranda and the numerous Campsis. The one depicted here belongs to the Pyrostegia genera that only include three or four species, all from tropical South America. Pyrostegia venusta often known as ‘flame-vine' is just stunning when in full bloom as the flowers appear in dense terminal clusters of bright orange trumpet shaped corollas. It is another huge plant which will reach the same dimensions as Merremia tuberosa which means it needs to be controlled and pruned quite drastically to be kept to a manageable size. The leaves are composed of three leaflets with one often ending in a tendril to allow the plant to grab available support. It is a common sight in gardens of Reunion where it often adorns a fence all around the garden but so far has not spread as it does not set seeds. The absence of seeds is probably due to the lack of a natural pollinator but is in no way a problem as cuttings root quite easily and the plant will even produce suckers. Its area of origin comprises southern Brazil, Argentina, Bolivia, and Paraguay. It enjoys full sun and will grow in almost any soil provided it is not clogged.
We will end with another member of the Bignonaceae family but leaving Latin America we will jump over the ocean again and land in Africa, more precisely in South Africa where we can admire Podranea ricasoliana (other synonyms are Pandorea ricasoliana, Podranea brycei and Tecoma ricasoliana). Common names are ‘pink trumpet vine' and ‘Port St-John's creeper'. It has a smaller size, reaching 5 to 6 meters (15 to 18 feet) in height, but will cover a wide area as trailing stems will soon produce roots and give birth to a new plant. Leaves are pinnate, bearing five to eleven leaflets. The fragrant flowers are a delicious shade of pink with darker pink veins and throats and come in loose clusters. It will enjoy loose and fertile soils in full sun and will also be easily propagated by cuttings.
This small tour of some vines of Reunion took us once again in a world-wide trip; I would bet that it will not be the last one we take together. See you all soon!