Senna surattensisCommon name: Glaucous Cassia, Scrambled Egg Tree, Golden Senna, Singapore Shower, Sunshine Tree, Sulphur-flowered senna • Marathi: Motha farvad • Kannada: Adavi tangadi, Bettadavare,
Glaucous Cassia is a small tree and very common in Southeast Asian gardens and is also often seen planted along citystreets and roadsites. The flowering days of Galucous Cassia are prolonged and beautiful. As a species, it is capable of flowering from January through December. Many trees have their best show in the spring and summer while others are at their showiest from fall into spring. The trunk and branches are a silver-gray color. The bright,sometimes pale yellow flowers appear continuously at the end of the branches. Flowers are very similar to those of Indian Laburnum, but never look so spectacular because they do not hang in bunches. Flowers attract butterflies. It is a rapidly easy growing tree,which tolerates poor soil.
Many trees have their best show in the spring and summer while others are at their showiest from fall into spring. Late summer and mid winter are usually the two periods of minimum or no flower displays, and mid winter is when many trees can become quite unkempt.
What’s quite noticeable is that most
trees, growing in close proximity to each other, either put on an exceptional show or nary a flower. This suggests that flowering is stimulated by local maintenance regimes more so than by changing weather. Newly planted trees must be kept well watered to become established and apparently to flower adequately.
After establishment reduce irrigation. In alternate years, prune once after a major flowering episode to keep a tight attractive canopy. You may want to prune more often since heavy flowering can leave some trees disheveled, with scant leaves and dry,hanging, blackened pods. The trunk and branches are a silver-gray color. The crown is naturally rounded and airy, but pruning and wind damage will thicken and shorten the canopy of many trees. Easily toppled by wind,S. surattensis should probably be staked for up to three years after planting or until it becomes properly established.It is generally not a long lived tree,and will usually not survive for more than 6 years under normal street scape conditions. However, properly tended, it can live for more than 10 years. This means keeping it properly standing and maintaining it free of scales and the pink hibiscus mealy bug. Typical of this genus,S. surattensis attracts egg-laying cloudless sulfur butterflies. The caterpillars feed on the leaves and flowers of the tree. However, caterpillar feeding does little to detract from the beauty of its magnificent displays. Maintain a fertilizer schedule for best appearance.
Senna species make good ornamental plants and are used for landscape gardening. The wide variety of species and ecological adaptations makes at least a handful of sennas suitable for any climate warmer than cool-temperate.
Cassia gum - a commonly-used thickening agent - despite its name, is actually from Chinese Senna (S. obtusifolia) seeds.In some Southeast Asian cuisines (particularly those of Thailand and Laos), the leaves and flowers of Siamese Senna (S. siamea, called khi-lek in Thai), either fresh or pickled in brine, are used in cooking, particularly in gaeng khi-lek (khi-lek curry).
Another senna, Senna italica ssp. italica (= Cassia obovata), often called "neutral henna", is used as a hair treatment with effects similar to henna but without the red color.
The active component is an anthraquinone derivative called chrysophanic acid(1,8-Dihydroxy-3-methylanthraquinone), also called chrysophanol, which is also found in higher concentrations in rhubarb root. It adds a slight yellow color. Chrysophanol has been reported to have antimicrobial and anti-inflammatory properties. It is also used by the beetle Galeruca tanaceti as a pheromone.
Some species of Senna are notable for being host to caterpillars of certain Lepidoptera species, for example
The sennas are typically shrubs or subshrubs, some becoming scandent when growing into other vegetation. Some are herbs or small trees. Many species have extrafloral nectaries.
The leaves are paripinnately compound, the leaflets opposite. The inflorescence is a raceme, or some arrangement or racemes. The pedicels lack bracteoles.
The flowers produce no nectar. They are buzz pollinated and offer pollen as a reward to pollinators. They are often asymmetric. The petals are 5 in number, similar to each other, yellow, or rarely white.
The stamens may be as few as 4, but usually there are 10. When 10, they occur in 3 sets. The 3 adaxial stamens are staminodial. The 4 medial stamens are smaller than the 3 abaxial stamens. The anthers are basifixed and open by two terminal pores or short slits.
The gynoecium is often enantiostylous; that is, it is deflected laterally to the right or left. This makes the flower asymmetric, but the perianth and the androecium may be asymmetrical as well.
The fruit is a legume, indehiscent or tardily dehiscent.
