Senna (Cassia Angustifolia) : 
Leaves and Pods of this Plant are used as laxative due to the presence of sennosides. Topical use of the leaves for dermatosis is also not uncommon.

Psyllium (Ispaghulla Plantago Ovata) : 
Also known as Isabgol.  Seeds of this Isabgol plant are cooling, demulcent, useful in inflammatory and bilious derangement of digestive organs. The husk from seeds has the property of absorbing and retaining water and hence used as an antidiarhoeal drug. Since it is also a bulk forming agent it is a very effective laxative used in the treatment of constipation. It is also added in packed cereal foods because of its high fibre content.

Available in the following forms :
Psyllium Seeds, Psyllium Husk, Psyllium Husk Powder.

Licorice (Glycerrhiza Glabra) : Roots of this plant contain sweet principal called glycerrhizine which is 40 times sweeter than table sugar. The roots are extensively used in ancient Ayurvedic and Unani medicines as demulcent and expectorant.
Available Roots and Powder. 

Ashwagandha (Withania Somnifera) :
Roots of this plant are used in various preparations of Ayurvedic medicines for hiccup, gynaecological disorders, bronchitis, rheumatism, stomach and lung inflammation and skin diseases indicated in general deblility, ageing, stress-induced disorders, rheumatic disorders, anxiety neurosis, wounds and ulcers. 
Available as Roots, Rootpowder and ashwagandharista.