Ocimum basilicum belongs to the mint family. It has an essential oil used in cooking and medicine. Its flowers occur in tiered spikes.
English: Ocimum basilicum, Lamiaceae, Sweet Basil, flowers. Deutsch: Ocimum basilicum, Lamiaceae, Basilikum, Blüten. (Photo credit: Wikipedia)
Ocimum basilicum, commonly called basil, belongs to Lamiaceae or Labiatae, the mint family. Other members of this family are salvia, beebalm, rosemary, and lavender.
There are various Ocimum basilicum varieties, and botanists have placed some types of basil into separate species. An especially interesting species is Ocimum tenuiflorum, otherwise known as Ocimum sanctum and commonly called tulsi. This species is held in high esteem in India.
The stems of Ocimum basilicum are supposed to be square in cross-section. This is an evident feature in some of my basil plants. In others, it is not so evident. A study conducted by Maria Zamfirache and others seems to confirm my observations. According to this study, variation occurred in the same plant. The upper portion of the plant stem was squarer than the lower portion of the same stem. Moreover, according to the TUN Institute, it is the younger stems that have a square cross-section.
My basil plants have opposite leaves with simple pinnate venation. Each pair of leaves grow at right angles to the pair immediately above and immediately below them. The leaves are fragrant, especially when crushed.
According to the Hamilton website, basil is a perennial when grown in the tropics. I believe that this depends on the variety because I live in the tropics and my basil plants last only part of a year. They last longer when the inflorescences are regularly removed as soon as they develop.
I have here a spike of basil flowers. The flowers occur in tiers or whorls along the length of the spike. Each flower is small and white in color. The corolla has a large upper lip and a small lower lip. According to “Fundamentals of Botany,” the upper lip consists of four fused petals, so that the total number of petals is actually five. It is hard to see the sepals on my basil flowers, but according to the TUN Institute, the five sepals of the calyx are likewise fused. The upper lip of the calyx has a single large sepal, while the lower lip consists of four fused sepals.