We will tour the garden and start with a small but nice flower, rather well known by gardeners in the tropics as well as chlorophyll addicts of temperate areas, Asarina scandens known as ‘climbing snapdragon' or ‘creeping gloxinia' belongs to the Scrophulariaceae family like the foxglove and displays flowers with the same shape as this familiar plant of the mountains. It is also found in books under its former synonyms of Lophospermum scandens, Maurandya scandens and Usteria scandens. It comes from Mexico like its close relative Asarina erubescens, which we met in the previous article, but A. scandens has more delicate features. The leaves are about half the size, shiny green and lacking hair, the petioles curve around available support to help the plant climb up. Flowers are small, but come in a profusion all year-round in tropical conditions, they are a nice purple with white throat, that will later on turn into papery capsules full of very tiny black seeds able to propagate the plant quite well though it does not have invasive status. As growth is quite fast, it can easily be enjoyed in temperate weather where it will be used as an annual. There are quite a few cultivars with different shades of purple and also white blooms.
Now a much bigger flower, also grown by enthusiasts as it usually stops any nature lover in its track, Gloriosa superba undoubtedly deserves its species epithet as the large corolla can reach ten centimeters across and displays bright yellow sepals turning red to maroon at the tip, reflexed and the long stamens protrude out like long insect antennas. This African-born lady produces leaves that are lanceolate and cling to surrounding branches by tendrils born from the tip of those leaves. A member of the Liliaceae family (some taxonomists now place it in the Colchicaceae family; it contains colchicine which is extremely toxic.) Though the Colchicaceae family groups some fifteen different genus, the Gloriosa genus itself has only one single species. It produces a subterranean tuber from which it will grow back every year. Those tubers can be dug out and put to rest for winter in temperate areas, or divided for propagation. As this plant is prone to variability there are different colored ones and even some are pure yellow.
Another showy flower is the large ‘cup and saucer' or ‘cathedral bells', a highly decorative vine that can become quite invasive if left uncontrolled. A member of the not-so-common Polemoniaceae family, Cobaea scandens is actually recorded as a weed in New Zealand. It comes from Mexico and is nowadays grown and even naturalized in many tropical locations and also enjoyed in cooler areas as annual due to its rapid growing habits and massive flowering. Easily reaching 6 to 8 meters (18 to 24 feet) with a profusion of leaves and flowers, it can cover rapidly any unsightly place of the garden. The flowers are bell-shaped, up to 5 cm long, they emerge greenish and will slowly turn to a spectacular purple. Leaves are divided in leaflets ending in branched tendrils themselves ending with hooks, a pretty effective tool for grapping. The seeds are large and flat.
In order to enjoy the next plant, we have to leave the garden and go to the Southern part of the island, the rain forest in the area of Saint-Phillipe will do the trick but we may need a light raincoat...This species has naturalized and can now be found in the wild in parts of the island, as it produces edible fruits it usually turns in a nice encounter, Passiflora alata is one of the 650 or so recorded species of passion flowers. Former synonyms are P.brasiliensis, P.mauritiana, P.oviformis and P.sarcosepala. Known as ‘maracuja de refresco' in Brazil, it is very closely related to the giant granadilla P. quadrangularis and sometimes confused with it. Both species do produce leaves and flowers quite similar, but P. alata always is on a smaller scale. To add confusion the species is prone to variation so there are numerous plants with great differences in the size and color of the flowers as well as size and taste of the fruits. Nonetheless the flowers are always showy, with 5 sepals and 5 petals, brightly colored in the inside (the sepals' outer side is green) ranging from crimson to pink, the corolla filaments reach 1 cm long, richly banded white and pale red. Leaves are entire, with no particular feature. The plant clings to its support like other passionflowers by means of tendrils. The fruit has the size and shape of a pear, ripening orange and quite tasty. This plant has been grown for ages in conservatories and has given rise to many hybrids such as P. x belotii which is a cross between P. alata and P. caerulea.
We will move now towards drier areas and go on the west coast where the climate is so favorable to Antigonon leptopus to the point where it seems to be part of local flora. It is typically an introduced and naturalized species, a plant that was brought from another place but which developed in such a way that it becomes part of the landscape. This member of the Polygonaceae family comes again from Mexico, it is one of the eight species amongst the genus, all from Latin America. Known as ‘coral-vine', ‘Mexican creeper', ‘chain of love', ‘coralita', it is widely grown throughout the world for its decorative effects and ability to grow in harsh conditions. On Reunion it has colonized many places on the dry coast where it happily thrives and produces masses of seeds, its tuberous roots make it well adapted to partial drought when it will loose leaves and stems and re-grow from stock as soon as rain starts. It does well in sandy to rocky soils, in full sun. The flowers come in clusters, most often a bright pink but they can also come out light pink and even completely white.
For the last species of this tour we'll stay on the west coast but wander a little in a ravine. Those ravines are fantastic places where many plants can be found, the remaining of semi-dry forests which used to cover the area before the coming of men as well as many species, exotic, indigenous and endemics. This one is a pantropical (found in most tropical areas). Its common names will give some clues about its properties; ‘velvet bean', ‘cowitch', ‘itch bean', ‘pica-pica'. For once you have accidentally come in contact with ripe beans you will never want to touch them again. Mucuna pruriens produces beans which are covered by orange hairs that cause intense itching if they touch the skin. Actually what causes the itches are not the hairs themselves but the two compounds they contain, mucunain and serotonin. Obviously a member of the Papilionaceae (former Leguminosae) family, the Mucuna genus contains some 100 species, among which the fantastic Mucuna bennetti from New Guinea, the famous ‘mucuna vine' or ‘red jade-vine'. Although he flowers of M. pruriens are not as showy as the ones of its New Guinea sister they still are impressive, consisting in a long pendulous cluster of deep purple flowers reminiscent of Wisteria. It is either an annual or short-lived tender perennial which will reach 18 meters (over 50 feet) long. Sometimes grown as fodder it is more often replaced by Mucuna pruriens var. utilis which lacks the irritating hairs.
We can now walk out of this ravine and go back to civilization, maybe enjoying a drink by the lagoon before heading home to the garden. We will anyhow be back as there still are around many interesting vines waiting for us to admire them!