In this article we will discuss about Fumariaceae:- 1. Characters of Fumariaceae 2. Distribution of Fumariaceae 3. Economic Importance 4. Affinities 5. Important Types.
Characters of Fumariaceae:
Plants with oil-containing sacs; leaves pinnate, much divided; flower zygomorphic, dissimilarity between two whorls of petals, by the saccate or spur-like development, two tripartite stamens, closed flowers with coherent to partially connate petals.
A. Vegetative character:
Habit:
Herbs with watery sap, sometimes lianous.
Root:
Root stock usually perennial.
Stem:
Herbaceous, branched diffuse or climbing.
Leaf:
Alternate, in basal rosettes or cauline, rarely sub-opposite, usually pinnately divided or dissected; leaflets small, thin, more or less lobed, exstipulate, in some petiole helps in climbing (Fumaria officinalis).
B. Floral characters:
Inflorescence:
Corymbose or racemose.
Flower:
Bracteate, pedicellate, bisexual, transversely zygomorphic, dimerous, hypogynous.
Calyx:
Sepals 2, small, scale-like, caducous.
Corolla:
Petals 4, erect, tips converging, sometimes basally connate, petals in 2 whorls, one (as in Fumaria, Corydalis) or (as in Dicentra), both of the 2 outer petals usually basally saccate or spurred, the inner ones narrower, crested and united over the anthers and stigma.
Androecium:
Stamens 6, united in sets of 3 each, the middle anther of each set 2-celled, lateral anther 1-celled, filaments somewhat winged and coherent to connate for much of their lengths, 1 or 2 nectar glands usually present at the base of the androecium.
Gynoecium:
Carpels 2, synacarpous, ovary superior, 1-loculed, placentation parietal, ovules 2-many; style 1 and slender; stigma 1, sometimes 2-lobed, dilated.
Fruit:
Capsule – transversely septate 2-valved or nut, indehiscent 1-seeded.
Seed:
Small, black endospermic.
Pollination:
Entomophilous.
Floral formula:
Distribution of Fumariaceae:
Fumariaceae or Fumaria family of 19 genera and about 465 species, is distributed mostly in the old world and primarily in temperate Eurasia.
Economic Importance of Fumariaceae:
1. Medicinal:
Fumaria in conjunction with black pepper serves as an efficacious remedy in common fever. Fumaria indica is diuretic, diaphoretic. Corydalis ramosa is used in eye-troubles. C. govaniana is diuretic and tonic.
2. Ornamental:
Dicentra officinalis, D. spectabilis are grown in gardens.
Affinities of Fumariaceae:
The systematic position of the family is to some extent controversial. Fumariaceae, according to many botanists, though it belongs to Papaveraceae, is a separate family with direct line of origin from Papaveraceae or its immediate ancestor.
Engler, Diels, Wettstein and other treated Fumariaceae as a sub-family under Papaveraceae; but zygomorphy in flower together with complexity in structure of androecium lead Lawrence to reckon it as a separate family under Rhoedales. Hutchinson recognised it as a separate family but included with Hypocoideae (another group of Papaveraceae). Hooker treated it as a separate family near Cruciferae under Thalamiflorae.
Common plants of the family:
1. Corydalis govaniana – diuretic and tonic.
2. Dicentra officinalis – Bleeding heart – ornamental, garden plant.
3. Fumaria parviflora – Common weed.
Important Types of Fumariaceae:
Fumaria parviflora – H. Pitpapra:
Habit:
An annual herb, growing wild in fields as a weed.
Root:
Tap-root, branched.
Stem:
Herbaceous, scadent, branched, juice watery.
Leaf:
Simple, much-divided, segments narrow and flat.
Inflorescence:
Racemose, 1-2 in. long.
Flower:
Small, whitish or pinkish, tips purple, pedicellate, complete; zygomorphic, bisexual, hypogynous.
Calyx:
Sepals 2, small, antero-posterior, greenish, inferior.
Corolla:
Petals of two whorls of 2 each, two petals in the outer whorl dissimilar, one flat or saccate, the second gibbous or spurred at the base for storage of nectar; 2 inner petals clawed, tips coherent, keeled, covering the stamens and stigma.
Androecium:
Stamens 6, tripartite, viz. united in 2 sets of 3 each, the middle anther of each set 2-celled, lateral anthers 1-celled; filaments somewhat winged and coherent to each other for much of their lengths, broad at base. One bundle (set of stamens) has a spur at the base projecting into the spur of the petal.
Gynoecium:
Bicarpellary syncarpous; ovary superior, unilocular; ovules 2, two parietal placentas; style slender, filiform; stigma entire or shortly lobed.
Fruit:
Globose, 1-seeded, as only one ovule matures, rugose when dry, rounded at the top with two pits.
Seeds:
Minute, black, albuminous.
Floral formula:
Unusual character of Androecium:
There are following views to explain the unusual character of androecium:
1. According to de Candolle, in each set, the two half (1-celled) anthers belonged to a pair of median 2-celled stamens, each of which had split, the halves being displaced right and left to become attached to the lateral 2-celled stamens, thus making them tripartite, each consisting of one complete anther in the centre and two half anthers attached laterally.
According to this view therefore, there are 4 stamens arranged in two whorls of 2 each.
2. According to Arber there are 6 stamens of which two are normal with dithecous anthers and four are reduced with 1-celled anthers.
3. According to Eichler there are only 2 laterally placed stamens having 2-celled anthers, while the other 4 with 1-celled anthers are their stipular appendages.
4. According to Asa Gray, each lateral group represents a single stamen which had become tripartite, and this is supported by the fact that during the development the whole structure develops from a single protuberance on the thalamus.
5. According to Norris, there are two whorls of 4 monothecal (1-celled) stamens. The characteristic tripartite condition is derived by the fusion of 4 outer monothecal stamens in two pairs, to each of which gets attached 2 monothecal stamens from the inner whorl laterally.