Artificial Habitat

Introduction

The range of the ecosystems so far dealt with are governed byone or more of the natural factors affecting them - for example light, temperature, humidity and kind of substratum all determine the limits of the development of the living being. Such surroundings may be referred to as "natural determinism". Gardens, flowerbeds, and parks are instead built everywhere man thinks it necessary and with criteria depending on the culture and on the level of civilisation the people have reached. In this way species with different natural requirements live next to one another thanks to the constant intervention of man. These kinds of surroundings are called "anthropical determinism". The annexing of the Canary Islands by the Spanish Crown during a period of intense trade with the colonies in South America combined with their position along the principal routes between the latter and Europe has enabled the introduction in the "Lucky Islands" of many tropical species which have easily become naturalised thanks to their hot-humid climate. The ornamental plants which can be found in the gardens of the Canary Islands do not only come from Latin America, but also from Australia, South Africa, India, Madagascar and south-west Asia.

Many of these plants contribute to make parks, streets and gardens look nicer thank to their colours and perfumes, but we must remember that the introduction of exotic plants may represent a form of environmental contamination as we introduce an extraneous subject which the nature of a particular area might not be able to integrate. Some species bring along the parasites they have in their native country, determining, in an different ecological context, infections difficult to control, sometimes causing great damages to the local ecosystems. On the other hand, these plants may not suffer from the local parasites and grow undisturbed and in such numbers they oust the wild flora.

In order to have exotic flora that continues to make our life brighter, but without damaging the natural local patrimony, it is necessary for man to learn to regulate his interference and restrict the use of these plants only to the artificial habitat, where nature has already let the infrastructures pass. The species described below are in strict alphabetical order, according to their scientific name.

Acalypha Wilkensiana

It is an evergreen shrub native of Malaysia, about 4.5 meters high. The elliptic leaves are simple, about 20 centimeters long, bronze-green with shades from copper to purple. The flowers are very small and grouped in spike-like inflorescences up to 10 centimeters long. It is grown to give colours to flower-beds and hedges.

Acokanthera Oblongifolia

It is an evergreen shrub native of South Africa. It can reach 7 meters in height. The opposite elliptic leaves are coriaceous, shiny and about 12 centimeters long. It is in bloom from autumn to spring and it has white flowers up to 2 centimeters large that are grouped in close inflorescences at the end of the branches and have a perfume very similar to that of jasmine. The fruits are globular, deep purple berries. All the constituent parts of this plant are poisonous and they were used by the natives to poison their arrows. It also has some healing proprieties.

Aechmea Disthicantha

This grass can reach 60 centimeters in height. Its narrow imbricated leaves are held in a very close basal rosette and are upright; their proximal part is widened with a triangular shape, while the distal part is narrow and long ending with an aculeus. The pink floral scape can be up to one meter high and at the end has several flowers subtended by bracts with short thorns. The small flowers are purple or blue. It is native of south Brazil and Uruguay.

Allamanda Neriifolia

This evergreen shrub can be up to one meter and half high, with branches having a igneous base. The elliptic leaves are up to 15 centimeters long, pointed at the end and grouped in verticils from two to five. The trumpet-shaped yellow flowers with yellow-red markings are grouped in inflorescences, but still distant from one another. It is used in gardens as a pot-plant or to cover walls and fences.

Alpina Zerumbet

It is a perennial grass with several aerial trunks (up to 3.5 meters high) leading off an underground rootstock. The lanceolate leaves have the expanded part up to 75 centimeters long and up to 15 centimeters wide, with vaginated petiole and with ciliated margin. The trilobated flowers are white with pink markings and are arranged in pendulous spikes. It is in bloom all the year and, for this reason, it is much used in floriculture. It is indigenous of south-east Asia.

Ananas Comosuni

The "pineapple" is a much utilised plant as its fruit can be both eaten fresh and used by the food packaging industry; moreover, from the fruits we can get a proteolytic enzyme similar to the pancreatic juice. It is also cultivated as an ornamental species for its flowers and leaves and there are many cultivars. It is a perennial grass whose leaves are held in a basal rosette. The leaves are up to a meter long and they may vary from a more or less bright green to reddish. They have a dentate margin with thorn teeth. A scape issues from the rosette:
it is usually 50 centimeters high, with an inflorescence consisting of many red-violet flowers arranged at the end of the scape itself. The fruit is very characteristic and it is an infructescence consisting of many fruits, up to 200 melted together with at the end a cluster of spiny leaves. In the cultivated variety "Honey-Gold" the fruit may reach 7 Kilograms in weight. The pineapple is native of Brazil, but at present it is cultivated in every region with hot-humid climate.

Aptenia Cordifolia

It is a small creeping shrub not higher than 50 centimeters. The opposite leaves are quite fleshy, with a short petiole and pointed apex. They are papillate. The purple flowers are single or grouped in clusters of 3-4. It is an indigenous plant to South Africa and cultivated as an ornamental species, particularly in the areas not far from the sea.

Bahuinia Variegata

It is a deciduous tree, up to 10 meters high, native of India. It is characterised by very wide foliage which is not close. The compound leaves are abruptly pinnate with lanceolate leaflets. It is also called the "Orchid Tree" thanks to its really beautiful flowers which are magenta variegated with purple and white and up to 12 centimeters in diameter. These flowers are grouped in lateral inflorescences arranged at the end of the small branches. There are some cultivars of this plant, and they differ from one another for the variegations of the flowers. The particular shape of the foliage makes it suitable to be planted along the roads also because, as most of the legumes, it has notparticular exigencies concerning the soil and it grows rapidly. Owing to its bark rich in tannin it is used as a dyer plant; in India its flowers and leaves are eaten.

Bouganvillea x Buttiana

IIt is an igneous creeping evergreen plant with thorns all along the trunk. The hairless pointed leaves are up to 20 centimeters long and with the undersides lighter than the upper pages. The small, hardly visible flowers are replaced in their function as vexillum by the purple calyx and by three bracts of the same colour, very similar in shape to the leaves. It is in bloom all the year and it has a rapid growth; for these reasons it has been cultivated for long time and there are many cultivars.

Brougmasia Versicolor

It is an evergreen tree, up to 5 meters high and native of Ecuador. The elliptic leaves have a tapering apex; they can vary from hairless to pubescent and be up to 60 centimeters long. The flowers vary from salmon pink to light peach pink, they are pendulous, up to 17 centimeters long and have a trumpet-shaped corolla owing to which the plant has been called "the Angels' trumpet". The fruit is a characteristic spindle-shaped berry up to 21 centimeters long. All the parts of this plant are poison as they contain a toxic alkaloid which, given in small amounts, can be used as a light narcotic. This plant is in bloom all the year, is tough, and has little cultural needs, therefore it is largely used in parks and gardens.

Callistemon Viminalis

IThe name means "plant with beautiful stamens", characteristic shared by many plants belonging to the genus Myrtaceae. It is a small tree, up to 5-6 meters high, with a close foliage consisting of flexuous branches from which the name of the species "viminalis" is derived. They are similar to those of the "basket-willow". The young branches have silky hairs. The lanceolate leaves are alternate. The small flowers are grouped in spike-like light red inflorescences. The species of the genus Callistemum tend to hybridise among them, therefore their identification is fairly difficult. This characteristic has been used to produce several cultivars. It is native of Australia.

Canna Indica

The genus Canna consists of 9 species of perennial rhizomatous herbs, up to 5 meters high often used to beautify gardens and to give them an exotic touch. They are all characterised by very long leaves (up to a meter long) with blades extending on the petiole which, in its turn, continues to form a false trunk. The flowers generally large and with different colours are arranged in terminal inflorescences. The "rattan" is up to 2 meters high, its leaves can be up to 50 centimeters long and 200 centimeters large, sometimes with purple veins. The flowers are solitaries or in couples: their red colour may tone to pink or to orange, with the lower petal sometimes variegated of yellow. It is an indigenous plant to Central America, but it is cultivated in all the regions characterised by a hot-humid climate. There are many cultivars of Canna Indica, enlarging the habit of colours of the flowers.

Canna Glauca

This plant is generally smaller than Canna Indica, from which it differs for the usually smaller flowers and for their lighter colour, tending to light yellow. Like the "rattan" and all the other Cannaceae it can be found wild only in Central America.

Carica Papaya

The "papaya" is a tree 4-8 meters high. The palmatedlobate leaves are up to 60 centimeters in diameter. This dioecious plant has yellow female flowers and pink or light yellow male flowers grouped in pendulous spikes up to 75 centimeters long. The plant is cultivated for his edible fruits, similar to yellow or orange-red water-melons: they can be picked and sold on the market or used in the pharmaceutical industry to get a digestive alkaloid: the papain. The papaya is native of tropical America.

Cassia Didymobotrya

(Leguminosae)

It is a shrub, up to 3 meters high. The compound, abruptly pinnate and persistent leaves are up to 40 centimeters long and consist of ovate-elliptic leaflets with mucronated apex. The bright yellow flowers are grouped in upright inflorescences, up to 30 centimeters long, arranged at the end of a long bent stalk. This plant is native of tropical Africa, widely used as an ornamental species in tropical and sub-tropical gardens for the chromatic effect of its flowers.

Cestrum Aurantiacum

It is a creeping shrub or a small tree, up to 6 meters high. It is native of Guatemala. The persistent ovate-lanceolate leaves are up to 15 centimeters long. The yellow flowers are grouped in pendulous spikes.

Cestrum Parqui

It differs from the other species of Cestrum for the always shrubby and upright habit and for the light yellow tending to greenish flowers. It is native of Chile.

Chamaerops Humilis

It is one of the smallest existing species of palms. It is wild in the countries around the Mediterranean, but it is cultivated in most arid regions. The short and wide trunk is rarely higher than 4 meters. The leaves are arranged at the end of the trunk, they are palmated and their expanded part is supported by a long petiole. The leaflets of the leaves are coriaceous, sharp and up to 30-40 centimeters long. It is a very ornamental plant, particularly if used isolated in open places.

Chlorophyon Comosum

This genus has a tropical and sub-tropical range and it reaches the maximum variety of shapes in South Africa, where it is indigenous. It is a rhizomatous herbaceous plant with persistent, linear and fleshy leaves, characterised by their green colour variegated of white, giving it an ornamental appearance. There are many cultivars, which can be distinguished for the variegation of the leaves.

Clivia x Cyranthiflora

This perennial grass has bright green leaves held in a basal rosette. The fleshy leaves are up in pendulous inflorescences. upto 90 centimeters long. The period of blooming covers all the year. It is a hybrid of orange-red flowers: they are trumpet-shaped, up to 5 centimetres long and grouped in pendulous inflorecences. It is a hybrid of artificial origin between Clivia miniata and C.noblis.

Clivia Miniata

It is a plant native of South Africa and it can be distinguished from Clivia cyrtantiflora by the smaller, darker and stronger leaves and by its flowers, which are upright and larger (7.5 centimeters long). It is in bloom from spring to the beginning of summer.

Coccoloba Uvifera

It is a tree, generally not very big, but which, with favourable conditions can reach 15 meters in height. It is characterised by big leaves, up to 30 centimeters in diameter, coriaceous, orbicular, with prominent protuberant veins. The tiny flowers grouped in inflorescences up to 30 centimeters long have a very strong smell. This plant is native of the Antilles, and it is suitable to be planted along the roads, particularly near the sea, because, not only because it has no particular exigency concerning the soil, but it is also resistant to marine aerosol and to pollution in general.

Codiaeum Variegatum

This evergreen shrub can be found in Moluccas and Malaysia where it is used by the natives both for producing clothing and as a healing plant. It is also used as an ornamental plant thanks to the variegation of its leaves. These are, in fact, variable in size and colour varying from green with yellow streakings to dark green with more or less bright red streakings.

Cordyline Stricta

The genus Cordyline, native of south-east Asia and Australia, gathers plants with a very characteristic habit, consisting of a rosette of linear long and narrow pointed leaves arranged on a small trunk, sometimes branched, leading off the ground. The leaves may have some thorns on the point and on the margins. When it is mature, a scape issues from the centre of the rosette: it can reach 4 meters in height, with the inflorescence on the top part. In this species the inflorescence is branched and consists of several lilac light blue flowers. There are some cultivated species differing for the variegation of the leaves.

Crinum Moorei

It is a perennial grass, with a floral scape up to 1 meter and half high. The linear lanceolate leaves are arranged at the base, up to 125 centimeters long and up to 15 centimetres wide, generally arched. The white flowers, rarely with pink markings, are very large and can reach 20 centimeters in diameter. It is an indigenous species to South Africa.

Echinocactus Grusonii

It is a succulent species with a globular trunk up to a meter wide. The ribs are few but evident and divided by deep grooves. The horns are up to 5 centimeters long, gathered in clusters consisting of 4 central thorns, golden in colour, and 10 radial, light yellow or whitish thorns. The flowers are yellow tending to brown. Echinocactus grusonii is native of Mexico.

Erythrina Caffra

This genus, with a tropical and sub-tropical range all over the world, consists of species with high ornamental value as they are characterised by very large flowers arranged in rich racemes. F. caffra is a deciduous tree, up to 18-20 meters high, native of South Africa. The branches are thorny. The compound leaves are odd-pinnate. The bright orange flowers are grouped in small pendulous inflorescences. It is in bloom in spring. There are several cultivars differing for the colours of the flowers. Some species of this genus have pharmaceutical importance as they contain some alkaloids with strong narcotic power. The bright red seeds are shiny and are used by the Bantu women for making lucky necklaces. As the wood is light, it is used for building canoes.

Erythina Corallodendron

It can be distinguished from Frythrina caifra for the bright red flowers grouped in racemes reaching 30 centimeters in length. The "tree of the coral" is a deciduous tree up to 3 meters high, with trunk and petioles covered by small arched thorns. The pinnate leaves are divided in three leaflets.

Espostoa Lanata

It is a small shrub or succulent tree up to 8 meters high. The main trunk, with a diameter up to 1 5 centimeters, is characterised by the presence of 20-30 veins not easily distinguishable owing to the close white egret. The central thorns can be one or two, triangular-shaped, pointed, up to two and half centimeters and whitish, brown or black in colour. The flowers can be white or purple and, usually are open during the night. It is wild in Ecuador and Peru but it is commonly cultivated in the arid areas all over the world.

Euphorbia Milii

It is an upright plant, up to two meters high. The irregularly branched succulent trunks have quadrangular or pentagonal section; they have straight thorns (up to 4 centimeters long) and can become creeping. The few leaves are small (not larger than 5 centimeters) and egg-shaped. The stalks are reddish. It is a plant native of Madagascar and its long and straight thorns have given it the name of "Christ's plant".

Euphorbia Pulcherrima

The "poinsettia" is probably the best known euphorbia in the world, but it is still very difficult to associate it with F. canariensis and F. Balsamifera. It is a shrub with few thin branches, not higher than 4 meters. The deciduous dark green leaves are up to 32 centimeters long. The inflorescence has the same characteristics as all the other euphorbiaceae, in this case the bracts around it are identical to the leaves, but bright red in colour. There are many cultivars with bracts varying in colour from red to white. This plant can be cultivated in a pot even in apartments.

Feijoa Sellowiana

It is a shrub about 6 meters high characterised by branches covered with a white tomentum. The persistent, opposite leaves are two-coloured, with a dark green upper face and a lower face covered with tomentum. The flowers are isolated, purple in the inner part and with tomentum on the outer one. The edible fruits have the same flavour as the pineapple. It can be found wild in south Brazil, Paraguay and Argentina.

Gazania Rigens

It is a creeping plant, closely covered with leaves generally having close whitish hairs on the lower face. On the very young leaves, the hair is present on the upper face too. The flower-heads are usually arranged at the end of a small branch and have lateral flowers with evident yellow-orange ligulas and dark orange central flowers. The species of the genus Gazania are often used to ornament walls and rocky gardens or flowerbeds along the roads as they do not suffer in an arid climate and some varieties can somehow stand a bit of cold. The genus is native of central and South Africa.

Grevillea Robusta

This tree, native of Australia, in its natural state can reach 30 meters in height, while in the cultivars it is much shorter. The persistent lanceolate leaves are white in their undersides and up to 35 centimeters long. The golden yellow flowers are grouped in inflorescences where every one is turned upwards. It is in bloom in the spring-summer, period during which grevillea becomes spectacular and for this reason it is widely used as an isolated tree in parks and gardens.

Hibiscus Rosa-Sinensis

(Malvaceae)

The genus Hibiscus consists of about 220 species, among which there are some of the most beautiful ornamental species, all characterised by beautiful flowers. H. rosa-sinensis is a shrub up to 4 meters high. The ovate leaves are toothed, especially in the apex, and they are about 15 centimetres long. The more or less deep pink flowers are in bloom all the year. The "Rose of China" is wild in most of tropical and sub-tropical Asia.

Hibiscus Calyphyllus

(Malvaceae)

It has the same morphologic characteristics as Hibiscus rosa-sinensis, from which it can be distinguished for the yellow flowers. Unlike H. rosasinensis, which is more common and of which there are many cultivars, H. calyphyllus is not much used in floriculture even if it is a wild species easily cultivated. It is native of tropical and subtropical Africa and therefore it needs a hot and humid climate.

Ipomoea Acuminata

(Convolvulaceae)

It is creeping plant native of tropical America. The ovate-rounded leaves can be trilobated when they grow bigger, and are tomentous in the lower face. The purple flowers have 10 orange markings and they are grouped in inflorescences consisting of few elements.

Iresine Herbstii

(Amaranthaceae)

It is a perennial grass, up to 1.8 meters high and characterised by the bright coloured trunks and leaves. In fact, the whole plant is purple red, variegated with more or less intense hues. There is a cultivar of this species (I. herhstii cv. aureoariculata) which is completely variegated in the shades of green. The flowers are insignificant. The wild species is native of South America.

Iacaranda Mimosifolia

(Bignoniaceae)

It is a very decorative tree of medium dimensions (it reaches 15 meters height) very suitable to be planted along the roads and to decorate parks and gardens. The composite leaves are abruptly pinnate with 9 couples of leaflets, and they reach 80 centimeters in length. The violet-blue flowers are grouped in hanging inflorescences. It is in bloom in spring and summer. It is native of the central areas of South America.

Macka Bella

(Acanthaceae)

This evergreen shrub, native of South Africa, can be up to two meters high. The opposite leaves are ovate, narrow and long, slightly toothed in the margins. The pale pink flowers are grouped in inflorescences arranged at the end of the branches. It suffers with cold winds; therefore the ideal place for its open cultivation is represented by the coasts.

Megaskepasma Erythrochlamys

(Acanthaceae)

It is a shrub, up to 2 meters high, native of Brazil where it is called "red mantle". The persistent, oblanceolate leaves are up to 30 centimeters long and have whole margins, more or less waved, and acuminated apex. The pale pink or white flowers are grouped in terminal spike-like inflorescences, and they are subtended by linear purple bracts up to 4 centimeters long. It is in bloom during the wintry months and it gives its best if planted in the shade.

Monstera Deliciosa

(Araceae)

It is a creeping igneous plant with aerial roots, sometimes very long. The persistent, coriaceous leaves have very long petioles, sometimes longer than the blade. The leaves are generally very big, up to 70 centimeters, deeply laciniated or with lacinias fused on the margins. The flowers are grouped in a milk-white spadix-shaped inflorescence protected by a widened spate of the same colour. "Monstera" is native of Central America.

Musa x Paradisiaca

(Musaceae)

It is a giant grass up to 8 meters high, characterised by a creeping rootstock from which the leaves lead off. The leaves, with the melted sheet, form a pseudo-trunk. The leaves have an expanded blade, up to 2.3 meters long, with a well evident reddish central vein. The flowers are arranged in a spike-like reddish inflorescence wrapped up in a bract. The male flowers are in the top part, the female ones at the bottom. The fruits are berries up to 9 centimeters long (the bananas) and are gathered in the famous "bunch". The genus Musa is native of the south-west Asia but it is commonly cultivated anywhere the climate allows it. M. x paradisiaca is a species of great food value and it constitutes the basic food of the diets in the poorest countries, but it is also a plant with a great ornamental value. The many cultivars tend to favour the production of fruits or the appearance of the plants themselves, producing forms always more suitable for the exigencies of the ornament of open spaces.

Nerium Oleander

(Apocynaceae)

The "rose-laurel" is a shrub up to 4.5 meters high. The persistent, linear lanceolate leaves are up to 25 centimeters long, and they are grouped by three in verticils. The flowers vary from more or less dark pink to white. It is a rustic plant of which there are many cultivars, differing both for their colours and for their double petals.

Odontonema Callistachyum

(Acanthaceae)

It is a shrub native of Central America, up to 5 meters high. The light green leaves are persistent, opposite, ovate-elliptic and up to 30 centimeters long. The pink tending to red flowers are grouped in spike-like inflorescences, up to 45 centimeters long which continue over the highest part of the branches. It is in bloom most of the year.

Pachycereus Pringlei

(Cactaceae)

It is a cactus of great dimensions as it may reach 15 meters in height. Its trunk is up to a meter in diameter and has 11-15 ribs. The thorns are strong and grouped in small clusters of 20 or more. They are about 3 centimeters, while the central thorn is slightly longer. The white flowers can remain open during the night as well. This plant is native of New Mexico.

Plumbago Auriculata

(Plumbaginaceae)

It is a creeping shrub with thin and flexuous trunks. The persistent leaves vary from oblanceolate to slightly spatuliform, up to 10 centimeters long. The light blue flowers have lighter hues: they are characterised by a long canal and an expanded part up to 3.5 centimeters in diameter; they are grouped in spherical inflorescences: it is native of South Africa, but it is cultivated in many regions as a fencing species.

Podranea Ricasoliana

(Bignoniaceae)

It is a creeping shrub native of South Africa. The persistent, opposite leaves are odd-pinnate, up to 25 centimeters long. They consist of 9-1 3 ovate leaflets, with a pointed apex of up to 10 centimeters long. The pink flowers have red markings and are grouped in sub-globular inflorescences.

Ravellana Madagascariensis

(Strelitziaceae)

The "Traveler's tree" as it is commonly called, is an herbaceous plant with giant dimensions as it reaches 16 meters in height. It is native of Madagascar. The name seems to derive from the fact that the travelers could always find some fresh water inside the large floral bracts and the flowers themselves. The trunk is simple, or branched at the base, and, as for all the monocotyledons, it consists of the sheaths wrapping up one another. The leaf blade reaches four meters length and it is carried by same length petioles, leading off the trunk at 45 degrees .The flowers are characteristic, but very similar to those if the other Strelitziaceae.

Senecio Cineraria

(Cornpositae)

It is an upright grass, whose trunk has a ligneous base, up to 50-60 centimeters high. It is characterised by silver-grey tomentum which covers it almost completely. The yellow flower heads are small and lie in the upper part of the trunk.

Solandra Maxima

(Sofanaceae)

It is a ligneous creeping shrub native of Mexico. The persistent, coriaceous and elliptic leaves are up to 25 centimeters long. They are pointed at the end and have a long petiole. The yellowish flowers have brownish markings in the inner part. They are very large and have a canal widening to a bell-shape. This plant is in bloom all the year, but at the height of summer.

Spathodea Campanulata

(Bignoniaceae)

This plant owes its great beauty to its showy flowers which have given it the name of "tulip tree". It is a medium dimensions tree, not growing higher than 20 meters. The persistent leaves are pinnate, up to 65 centimeters long and consisting of leaflets up to 12 centimeters long. The bright red campanulate flowers have yellow-gold margins and they are up to 7 centimeters long. They are grouped in globular inflorescences at the end of the branches. This rustic plant is very suitable to be planted along the roads.

Strelitzia Reginae

(Strelitziaceae)

The species of the genus Strelitzia (native of South Africa) are giant herbs which can reach 10 meters in height. The trunk, as for the genus Musa (Musaceae) and Ravelana (Strelitziaceae) is herbaceous but is it very large in diameter and it consists of the leave sheaths wrapping up one another. The blades are really large (they can reach 70 centimeters) and have a petiole reaching even 2 meters length.S. reginae or "bird of paradise" is one of the smallest species, as the floral scape is never higher than one and half meters. The leaves are up to 1.7 meters long, including the petioles. The orange or yellow flowers have a deep blue lower part. It is one of the most used plants in floriculture, both as a pot-plant or as a cut-flower.

Strelitzia Nicolai

(Strelitziaceae)

It differs from S. reginae especially for its dimensions, reaching as it does the maximum values of the genus. The floral scape reaches 10 meters height and the leaves can be 4 meters long, two meters belonging to the petioles. The white flowers have a lower part varying from blue to purple. This plant is in bloom practically all the year.

Tecoma Stans

(Bignoniaceae)

This shrub, native of central and South America, can be up to 6 meters high. The leaves consist of 5-1 1 leaflets and reach 10 centimeters. The yellow flowers are campanulate and grouped in inflorescences at the end of the branches. It is in bloom all the year.