In this article we will discuss about:- 1. Characters of Sapindaceae 2. Distribution of Sapindaceae 3. Economic Importance 4. Affinities.
Characters of Sapindaceae:
Trees, shrubs or climbers usually pinnate leaves, the spring like circinately, coiled tendrils of lianous genera. Flowers polygamous or polygamodioecious; the scale or gland-appendaged petals; unilateral extrastaminal disc, tricarpellate ovary, trilocular, superior and usually arillate seed.
A. Vegetative characters:
Habit:
Trees, shrubs or climbers with watch-spring like tendrils.
Root:
Tap, deep in tree species, branched.
Stem:
Erect, or weak, climbing by tendrils which are axillary and represent the modified inflorescence axis. They are forked at the apex and the branches are often flat and rolled like a watch-spring.
Leaf:
Alternate compound, pinnate, stipulate (climbing species), stipules small and soon falling off, sometimes imparipinnate, the end leaflet of a paripinnate leaf is bent round to serve as a terminal leaflet. Latex or resin present in special sacs or cells in the lamina.
B. Floral characters:
Inflorescence:
Cymose, unilateral, cymes arranged in racemes or panicles.
Flower:
Obliquely pentamerous, zygomorphic, or actinormophic, bisexual or unisexual, hypogynous, polygamous or polygamodioecious, extra staminal disc is unilateral or glandular.
Both bisexual and unisexual flowers are found in the same individual (polygamous) or bisexual and staminate or bisexual and pistillate flowers (polygamo-dioecious) occur in separate individual plants.
Calyx:
Sepal 5, polysepalous, imbricate, in actinomorphic flowers sepals become 4 by the union of 3rd and 5th.
Corolla:
Petals 5 in actinomorphic flower becomes to 4 as a result of suppression of one of the five petals, polypelatous, with hairy or scaly appendages, Petals are absent in Schleichera, Dodonaea etc. Between petals and stamens the floral axis is developed to form a disc, which is generally ring-like and bears glandular swellings opposite the petal insertions.
Androecium:
Stamens 8 or 10, in two whorls, polyandrous, inserted inside the dise; dithecous, basifixed, introrse.
Gynoecium:
Tricarpellary, syncarpotfs; ovary superior, trilocular, with one or two ovules in each loculus, axile placentation; style terminal; stigma trifid.
Fruit:
Capsule, nut, berry, drupe.
Seed:
Arillate, non-endospermic.
Pollination:
Entomophilous.
Floral formula:
Distribution of Sapindaceae:
Sapinadaceae or Litchi family or soap-berry is an important family with 158 genera and 2230 species. In India the family is represented by 24 genera and 72 species. Commonly found in North Eastern and North Western Himalayas. The family is mainly restricted to tropical and sub-tropical regions.
Economic Importance of Sapindaceae:
1. Food:
Species of Pappeae, Melicocca, Euphoria, Nephelium and Litchi yield edible fruits with sweet, fleshy aril. Acer saccharinum a native of North America is the source of maple sugar. The maple sugar is obtained from the juice of stem. Paullinia cupania yields quarana’, a stimulant used as a beverage.
2. Medicinal:
The roots of Cardiospermum halicacabum are diaphoretic and diuretic and given in decoction as aperient. The leaves are administered in pulmonic complaints and mixed with castor oil are externally applied in rheumatism and lumbago. The leaves mixed with jaggery and boiled in oil, are specific for eye sore. Dodonaea uiscosa and species of Allophylus are also medicinals.
3. Soapy lather:
Sapindus saponaria or soap berry – Ritha yield fruits, which contain saponin and yield lather with water that is used for washing woolen and silken clothes.
4. Timber:
Schliechera oleosa yield Ceylon oak – a good timber.
5. Ornamental:
Koelreuteria paniculata (varnish-tree) and Xanthoceras sarbifolia are cultivated as hardy ornamentals.
Affinities of Sapindaceae:
Sapindaceae is allied to Anacardiaceae from which it differs in having compound leaves, spring-like circinately coiled tendrils, of lianous genera, usually irregular flowers, more than 5 stamens, typically tricarpellate ovary and usually arillate seeds.
The family Sapindaceae owing to the tendency of unisexuality in flowers, presence of definite number of ovules with ventral raphe, tricarpellary pistil, and arillate seeds bears close affinity with Euphorbiaceae.
Common plants of the family:
1. Litchi Chinensis – Litchi – fruit having sweet fleshy edible aril.
2. Euphoria syn. Nephelium, N. longana (Longon) – yield sweet fleshy edible aril.
3. Sapindus – Latin Sapo and indicus; Indian Soap berry Ritha.
4. Cardiospermum – From the Greek cardia – a heart and sperm, a seed, referring to the heart – shaped excrescence on the seeds.
5. Dodonaea – evergreen shrub, flowers without corolla.
Division of the family and chief genera:
Based on the characters of the ovule, the Sapindaceae is divided into two subfamilies:
Subfamily I. Dyssapindoieae:
Ovules 2 or more in each loculus, erect or pendulous with upwardly micropyle.
Examples:
Dodonaea, Turpinia, etc.
Subfamily II. Eusapindoieae:
Ovules in each loculus, erect, with downwardly microphyle.
Examples:
Nephelium, Sapindus etc.
Morphology of tendril:
The tendril in climbing species is the metamorphosed peduncle or its branch e.g. Cardiospermum helicacabum, a common tendril climbing under-shrub of Bengal, in which the main axillary peduncle gives off three branches, two of which are metamorphosed into watch-spring-like coiled tendrils, the other one end in cymose inflorescence.
Range of floral structures in the family:
Both regular and irregular flowers are met with in the (Syn. Euphoria) Sapindaceae. The flowers are regular in Litchi, Nephelium and Sapindus, but irregular in Allophyllus, Cardiospermum and Erioglossum.
Both unisexual and bisexual flowers occur in the same plant; these flowers are polygamous. Sometimes, bisexual and staminate flowers or bisexual and pistillate flowers are found in separate plants; these are polygamo-dioecious.
Variation takes place in the number of petals. The petals are absent in Dodonaea, Schleichera and others.
The number of stamens varies from the genus to another. The stamens are frequently 8, but 5 in Turpinia and numerous in Deinbollia.
The style is mostly 1, but rarely 2-4 and 1- to 3-lobed. The ovary is usually trilocular; rarely, the loculus number is 1, 2 or 4.