According to my information the common tulsi plant, the Sacred basil or holy basil, botanically Ocimum tenuiflorum L.(syn: O. sanctum L.) is called Krishna tulsi. In fact two types of plants are known for this species: one with green leaves and stem is Sri Tulsi and one with purple leaves and stems as Krishna Tulsi. The essential oil has antibacterial and mosquito repellent properties, leaves used in catarrah, expectorant, in bronchitis , malarial fevers, cutaneous diseases and ringworms.
Ram tulsi (also known as ban tulsi) is Ocimum gratissimum, the shrubby tulsi, having much more stronger scent and often planted as mosquito repellent. used as relief of ear-ache, tooth-ache, also used in cough mixtures. Herb also used in aromatic baths and fumigations for rheumatism and paralysis.
Dr. Gurcharan Singh
Retired Associate Professor, Department of Botany, SGTB Khalsa College
University of Delhi, Delhi-110007
Res: 932 Anand Kunj, Vikas Puri, New Delhi-110018
Phone: 01125518297; Mobile: 9810359089