Variation in different varieties of Portulaca

Jul 16, 2018 • 6:32 AM UTC

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JDua

Dr. Jasveen Dua Assocaite Professor Dept. of Botany GGDSD College, Chandigarh (INDIA)

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In our college garden variously colored Portulacas are blooming. I was fascinated by the various colours and types and observed their behaviour closely. They are a typical case of Photoperiodism (day length).
Commonly called as the Time Flower (Dopahar Khidi in Punjabi), as the flower opens and closes at specific times of the day. Portulacas need six to eight hours of full sun to bloom. Usually the flowers close at night and on cloudy days. Portulacas are drought tolerant and tolerate periods of dryness. They have a spreading growth habit and are ideal as a groundcover for gardens, rocky pockets and between pavings, where they quickly spread as a brightly colored flower carpet.
Many varieties have semi-double to fully double flowers that resemble miniature roses so often called as Rose moss . Flowers come in hot colors , like yellow, orange, red, and bright pink as well as white, cream, and variegated colors.
I could locate two types of flowers single petaled and double petaled blooming in the garden. The different types of Portulaca differed not only in their foliage but also their essential and non-essential organs, when seen under a foldscope.
It was seen that the flowers opened in the morning around 8.00 a.m and then found closed around 2 p.m and again they were open in the late afternoon till sunset.

The honey bees were found actively visiting the brightly coloured pink, red and orange flowers as compared to yellow and white ones.

The flowers with single flowers had slightly broader, ovate foliage, while the double flowered plants had linear and narrow leaves.

Single petaled Portulaca foliage (left) Double petaled Potulaca foliage (right)
The number of petals in single variety flowers were only five, while in double numerous petals in many whorls could be seen. The single and double flowers also showed variability in their pollinating systems. Pollen showed a high germination percentage on stigmatic surfaces. The two types of flowers had different status of pistils at full opening of the flowers : one with full spreading and the other with including stigma lobes of the pistils. Length of styles differed between these two types of flowers and so did the stigmatic lobes. The single flowers had numerous stamens surrounding a fully spread exerted 3-5 stigma lobes. The stamens of these flowers were shorter in length then the pistil. The stamens had slightly curved filaments. The double flowers had filaments of variable length. Presence of petaloid stamens was also seen in such flowers and the filaments were thin and cylindrical. However, no variability in pollen size or exine pattern could be seen. Both the types of flowers had trichomes present near the base of the style. Variety 1 Pictures follow: