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In this article we will discuss about the classification of Dilleniidae:- 1. Tiliaceae 2. Sterculiaceae 3. Violaceae.
Family # 1. Tiliaceae:
Salient Features of Tiliaceae:
Generally trees like basswood, Linden etc. Leaves alternate flowers in cyme, in Tilia peduncles adnate half its length to a large membranous bract peristing in fruit aiding in dispersal.
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Vegetative characters of Tiliaceae:
Generally Trees (Tilia) or shrubs (Grewia, Sparmannia), rarely herbs (Corchorus), non-laticiferous and without coloured juice, plants covered with stellate hairs, mucilage cells are distributed in pith and cortex of stem.
Leaves:
Alternate, Rarely opposite, simple, petiolate, non-sheathing leaf base, Lamina dissected entire, caducous in Tilia conspicuously asymmetric (commonly), pamatifid palmately veined, stipulate, stipules intrapetiolar, free, caducous or persistent.
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Floral Characters of Tiliaceae:
Inflorescence:
Generally, cymose in Tilia the inflorescence arises from a short branch in the axil of foliage leaf with a conspicuous membranous bract, adnate to the peduncle or primary axis of inflorescence, some species have solitary flower also.
Flowers:
Complete, generally hermaphrodite, sometimes unisexual, plants are monoecious, pentamerous, free hypanthium absent, flowers generally pentamerous, actinomorphic, hypogynous.
Perianth:
Distinct calyx and corolla present, rarely corolla absent.
Calyx:
3-5, polysepalous or gamosepetlous due to connate at the base, imbricate, epicalyx present or absent.
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Corolla:
3-5, polypetalous imbricate or contorted, petals may be deeply bifid.
Androecium:
10- many stamens free or fascicles, inserted at the base of petals or on an androphore, polyandrous, or coherent, all stamens fertile, Grewia has androgynophore, Sometimes the fascicled stamens are explained as poly adelphous, diplostemonous, anthers dithecous, introrse, opening by apical pores or longitudinal slits.
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Gynoecium:
3-10 syncarpous, 1 — ovules in each locule axile placentation or uniolocular with parietal placentation, rarely free central style one, in Tilia the ovary is pentalocular with two ovules in each locule, at maturity only one develops into a seed.
Fruit:
Fleshy, non-fleshy — dehiscent or indehiscent, or schizocarpic. It may be nutlet, samaroid or drupelet. Capsule or drupe is common.
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Seed:
Endospermic, endosperm oily
Economic Importance of Tiliaceae:
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Fibre:
Corchorus capsularis: Bast fiber yields jute.
Corchorus olitorius: Bast fiber yields jute.
Edible:
Grewia asiatica: Fruits edible (Phalsa)
G. subinaequalis: Fruits edible (Phalsa)
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G. elastica: Fruits edible (Phalsa)
Medicine:
Corchorus capsularis: Roots as medicine in dysentery and diarrhoea.
C. olitorius: Roots as medicine in dysentry and diarrhoea
C. microcos: Plant used in eczema.
G. tiliaefolia: wood is emetic and antidote for opium.
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G. villosa: Roots used in diarrhoea.
Trimfetta bartremia: Leaves, flowers and fruits in gonorrhoea.
Ornamental:
Sparmannia africana (House lime)
Tilia tomentosa (White linden)
T. europaea (European linden)
T. americana (Basswood)
Muntingia calabra
Grewia sp.(Phalsa).
Timber:
Berrya sp.
Tilia sp.
Elaeocarpus
Other uses:
Leaves of Grewia sapida. G. hirsuta, G. glabra etc. are used as fodder for cattle.
Elaeocarpus roexburghii:
The dried fruits are called Rudraksh. Now it is separated from Tiliaceae.
The family Tiliaceae is not a part of APG II but is found all through the botanical literature and remains prominently listed by nomenclatural databases such as IPNI. All through the existence the family has had a very lively history as various authors have various views as what should be part of this family.
Then it was recommended when this name is encountered to be careful to check what an author means when he uses this name. In north temperate regions the name is unambiguous as the only representative is Tilia the lime or linden.
As per de Candolle system Tiliaceae includes Sparmannia, Heliocarpus, Corchorus, Triumfetta, Grewia, Tilia, Muntingia, Apeiba, Berrya, Ablania etc.
Cronquist in 1981 included 15 genera with seven hundred species. Generally trees or shrubs, rarely herbs, Subcosmopolitan in distribution. Tiliaceae was separated from Malvaceae by smooth surface of pollen grain, bilocular anthers and the free stamen or fascicled stamen.
The APG II system does not recognize this as a family but submerged it in the Malvaceae sensu lato, which unites Malvaceae sensu stricto, Bombacaceae, Sterculiaceae and Bambacaceae. The family Malvaceae seusu lato is divided into subfamilies viz., Tilioideae, Brownlowooideae, Grewioideae, Cladislically, the traditional family Tiliaceae is Polyphyletic.
In APG II system the current placement of the genera is mostly in the new Malvaceae seusu lato, but Gyrostemon moved to family Gryostemonaceae, Muntingia to Muntingiaceae, Sloanea to Elaeocarpaceae, Vatica to Dipterocarpaceae and Wikstroemia to family Thymeleaceae. The genus Abatia is taken to new Salicaceae sensu lato.
Family # 2. Sterculiaceae:
Vegetative Tracers of Sterculiaceae:
Sterculiaceae is a family of flowering plants with 65 genera and 1000 species distributed in tropical and substropical regions of the world. Theobroma cacao is native of tropical America.
Generally trees (Sterculia, Pterospermium. Helectres), Shrubs (Walthria, Malhania, Dombeya) or Herbs (Pentapitis).
Leaves:
Alternate, simple or palmately lobed or compound, stipulate, stipules caducous, Younger parts of leaves and stem are covered with stellate and pubiscent hairs.
Floral Characters of Sterculiaceae:
Inflorescence:
Terminal and axillary racemose or cymose type, Cauliflory is found in Theobroma cacao.
Flowers:
Actinomorphic or rarely zygomorphic (Helectres) and bisexual rarely functionally unisexual . Unisexual condition is generally due to abortion e.g., Sterculia, Cola. Plants are Dioecious, hypogynous, pentamerous (Sterculia); androgynophore present.
Perianth:
Generally uniseriate, consists of 3-5 valvate, basally connate sepals but sometimes equal number of petals are also present. Petals absent in Sterculia and Cola.
Androecium:
Most frequently consists of two whorls of 5 stamens each, these are united by their filaments into a tube surrounding the ovary or arises from an androgynophore. The stamens of outer whorl are antesepalous with reduced to staminodes or absent (Walthria), while inner whorl is antepetalous and fertile. Monoadelphous in Malhania, sessile in Sterculia, anther dithecous introse, longitudinal slits, coiled apically.
Gynoecium:
Gynoecium consists of a single, compound pistil of usually 4-5 sometimes weakly associated carpels, an equal number of distinct or variously connate styles, and a superior ovary with usually 4-5 locules, each with 2- several axile ovules. Sometimes the ovary is present above petals due to androgynophore.
Fruit:
Dry or fleshy, dehiscent or indehiscent, woody capsule (Pterospermum), follicle spirally twisted (Helicteres). Sometimes the carpels are completely distinct at maturity.
Seed:
Endospermic, embryo with two folds and leaf-like cotyledons.
Pollination: Entomophilous.
Economic Importance of Sterculiaceae:
1. Cola acuminata: Colanut, nuts contain Caffein and are chewed to overcome fatigue. Seeds also used as refreshing drinks.
2. Brachychiton acerifolium: flame tree,
3. Dombeya: Ornamental plant
4. Guazuma ulmifolia: West Indian Elm, fruits edible.
5. Firmiana colorata syn. Sterculia colorata: Samari; Bark yields fibre used for ropes and cordage, leaf as fooder.
6. Sterculia foetida: Skunk tree, wild almond, seeds edible
7. Theobroma cacao: Cocoa, seeds and fruits are source of chocolate
8. Sterculia banghas: Seeds edible
9. Sterculia guttata: Hirik. Bark fiber used to make cloth.
10. Sterculia urens: Kateeragum, gulu, stem yield a gum used as substilute in calico painting.
11. Helicteres isora: Marorphali, Twisted dried fruits and roasted, seeds used in stomach troubles. Juice of roots is given in diabetes.
12. Heritiera littoralis: Looking glamtree, wood used in making sticks.
13. Ptercygota alata: Buddhaa coconut.
14. Pterospermum: Ornamental. Wood used as timber.
15. Walthria indica: Uhaloa, Plants used to brew a tea for treating sore throat.
Systematic Position:
Hutchinson placed Tiliaceae with other families in Tiliales. Previous workers kept it under Malvales. While Cronquist kept Sterculiaceae in order Malvales with other families like Elaeocarpaceae, Scytopetalaceae, Tiliaceae, Bombacace and Malvaceae.
Family # 3. Violaceae:
Violaceae is also called as Alsodeiaceae J.G. Agardh, Leoniaceae DC and Retrosepalaceae Dulac. The family consists of 800 species and 21 genera. The name Violaceae is given on the genus Viola the violet and pansies.
Salient Features of Violaceae:
Generally herbs, flowers zygomorphic, Pentamerous, petals 5, the anterior ones spurred, stamen 5, frequently 1 is spurred at the base. Flowers hypogynous with a single style.
Vegetative Characters of Violaceae:
The plants are cosmopolitan in distribution. But abundant in tropical regions of the world. Genus Viola is the largest genus. Plants are herbs (Viola), which may be perenial or annual some shrubs or undershrubs (Ionidium, Alsodei roxbugii) or occasionally small tree (Alsodeia maingayi) Anchietea is a climber. Propagate by runners.
Leaves:
Simple, alternate or opposite, leafy stipules or reduced stipules. Leaves may be heart shaped, toothed or finely cut. In alpine species (Rosulate violas) the leaves are almost round and form a dense ball or cushion, sometimes look more like s cactus or a pine cone than a violet. Radical in (Viola).
Floral Characters of Violaceae:
Inflorescence:
Solitary axillary (Viola), raceme (Rinorea), In Viola tricolor flower arises singly on long stems from the leaf axils.
Some species have cleistogamous flowers produced after or before the production of typically petaled flower. They set viable seeds.
Flower:
Bracteate, Bracteolate, Bisexual or unisexual (Melicytus) typically zygomorphic in herbeceous species and actinomorpic in arboresent species, pentamerous and hypogynous.
Calyx:
5 sepals, free imbricate.
Corolla:
5 petals, polypetalous, anterior petal spur or sac and largest (herbaceous), imbricate; The five petals may be unequal in size, the spore contains nectar, there are honey guidelines directing insects into the spur to pollinate the flower. Wild violets and violas are often blue, white, purple (violet) and yellow but hybrids are in many colours.
Androecium:
5 stamens, polyandrous, In Viola the connective of anterior pair of anther are produced into spurs project into the spur of corolla, filaments short anther dithecous and introse. In Viola the introrse anther form a close tube round the ovary below the style. At the tip, the connectives usually produces membranous appendage.
Gynoecium:
Tricarpellary, syncarpous, superior, odd carpel anterior, parietal placentation, style short simple and terminal, stigma hooded.
Fruit:
Capsule, which burst by explosive mechanism. In cleistogamous. Flower of Viola odorata and V. hirta the fruits are berry or nut.
Seed:
Testa hard and shiny, Elaiosome is present on raphe and dispersal is by myrmecochory seeds winged in Agatea and Anchietea, endospermic
Economic Importance of Violaceae:
1. Hybanthus ipacacunha is false epaca cunha used as medicine.
2. Viola odorata: Banafsha or sweet violet flowers used is perfumery and as demulcent in lung problems
3. Ionidium sp.: Ratanpures— The roots are used as medicine in bowel troubles of children.
4. Viola tricolor: Pansy— Ornamental herb.
5. Viola palustris: March violet— Ornamental herb.
6. Viola patrini: Wild violet— Ornamental herb.
7. Viola sylvestris: Wood violet— Ornamental herb.
8. Viola canine: Dogviolet— Ornamental herb.
Systematic position:
Cronquist placed Violaceae in order Violales of Dilleniidae. However, in APG system this family is placed in order Malpighiales.
