In this article we will discuss about:- 1. Characters of Portulaceaceae 2. Distribution of Portulaceaceae 3. Economic Importance 4. Affinities 5. Important Types.
Characters of Portulaceaceae:
Leaves fleshy, stipulate – hairy or scarious, 2-5 styled unilocular ovary with 2 to many campylotropous ovules on a basal central placenta.
A. Vegetative characters:
Herbs – annual or parennial or undershrubs.
Tap, branched, fleshy in Lewisia.
Herbaceous, prostrate or semi-erect, succulent, with scarious or hairy stipular appendages.
Simple, alternate or opposite, entire, succulent, stipulate – stipule scarious or hairy; rarely exstipulate as in Claytonia.
B. Floral characters:
Cymose, racemose or solitary.
Bracteate or ebracteate, hermaphrodite, actinomorphic, showy, complete, hypogynous or perigynous.
Sepals usually 2, often persistent, free or united at the base. Some regard sepals as bracteoles, and according to them the flowers have petaloid perianth.
4 to 6 petals, free or united at the base, caducous, usually imbricate, valvate in Claytonia; showy.
Stamens 4 to many, free stamens; usually 5 stamens, opposite to petals; anthers dithecous, introrse, dehiscing longitudinally; stamens 2 in Montia and 8-10 in Portulaca oleracea.
Usually tricarpellary, syncarpous, superior but partly inferior in Portulaca; unilocular; 2 to many campylotropous ovules on a central basal placenta; styles 2-5; stigma 2-5 or as many as carpels.
Capsule rarely nut. Capsule with circumscissile or loculicidal dehiscence.
Globose – reniform, endospermic embryo curved around the perisperm.
Distribution of Portulaceaceae:
It is represented by about 20 genera and 500 species. From India only 7 species have been reported.
Economic Importance of Portulaceaceae:
Portulaca oleracea is used as pot herb and in salad.
Portulaca oleracea is also used in the ailments of kidney and urinary bladder. Portulaca quadrifida is effective in cough and asthma.
Many garden varieties of Calandrinia, Lewisia, Portulaca and Talinum are cultivated.
Affinities of Portulaceaceae:
Bentham and Hooker included the Portulacaceae in the Caryophyllales. Rendle Lawrence placed it under the Centrospermae. Like the Caryophyllaceae, the Portulacaceae has come from the same source – the Phytolacaceae. The floral type of Portulaca evolved by the disappearcence of the inner whorl of capsules and by the juxtaposition of a pair of bracteoles to the flower to form the dimerous calyx.
The Portulacaceae shows close relationship with the Basellaceae, as the genera Portulacaria and Phillippiamra stand intermediate between the two families. Within the Portulacaceae, the genera with fewer number of stamens are considered to be more primitive.
Common plants of the family:
1. Portulaca grandiflora – Rosemoss – a garden annual with showy red coloured pollen flowers.
2. Portulaca oleracea – with golden yellow flowers – weed of waste places.
Important Type of Portulaceaceae:
Portulaca oleracea (vern. Kulfa, Salunak Fig. 36.1):
A stout succulent glabrous annual weed, flowering through greater part of the year and often used as a pot-herb. Flowers open during noon.
Herbaceous, prostrate or ascending, branched, succulent.
Alternate or sub-opposite, clustered at the ends of the branches, 1 to 4 cm. long, very short-stalked, thick, cuneate, oblong or spathulate, truncate, or retuse at the apex; stipular appendages minute or 0.
Terminal cluster of sessile flowers.
Ebracteate cyclic, actinomorphic, bisexual, hypogynous or half-inferior, bright- yellow.
2 sepals, free, green, anterio-posterior, acute, persistent.
5 petals, free, bright-yellow, perigynous.
Stamens 8-12, free.
Carpels 3-5, syncarpous; ovary half-inferior, 1-celled, ovules many on a basal placenta; style 3—5—fid; stigma minute.
A capsule, dehiscing transversely.
Many, minute, reniform, dark-brown, endospermic.