“Basils 2025” – Fourth Report: How can you easily distinguish between different species of Basil?

Summary

Besobila from Ethiopia. “*Ocimum bisabolenum*”

Foreword

That being said, and presented photographically, an human being who genuinely cultivates an intimate connection with species of Basil, of the genus Ocimum, will recognize them “at first sight” – that is, at the mutual rebirth of this connection.

This mutual connection is established, once again, in a holistic manner—that is, with the plant perceived in its entirety: its habit, its flowers, its pollen, its leaves, its bracts, etc.

Thus, all the main species of Ocimum, presented below, can be recognized “at first glance,” with the occasional exception of certain ecotypes of Ocimum americanum sp. pilosum… which can, nevertheless, be recognized “at first touch” – that is, at the first whiff of Citral when their leaves, or flower tops, are gently touched.

It should, also, be noted that certain ecotypes of the “purpurascens” type, of Ocimum americanum sp. pilosum, with chemotypes other than Citral predominating, are difficult to differentiate from Ocimum basilicum at first glance. These include, for example, the ecotypes “Anis” (Richters Seeds. Canada) and “Nouvelle Guinée” (Kokopelli). This is why many studies continue to present them as such, even though geneticists have formally placed them in the same genetic clade as Ocimum americanum sp. pilosum.

In fact, if I may digress into somewhat philosophical considerations, Basil species are like the Peoples of the Earth. The Ocimum genus is an “Archetype,” but it is not manifested in physical reality: it only has an informational (genetic) reality.

It is the diverse species of the genus Ocimum – Ocimum basilicum, Ocimum bisabolenum, Ocimum kilimandscharicum, Ocimum tenuiflorum, Ocimum gratissimum, etc. etc – that constitute the manifestations, the “Chlorophyll sub-Archetypes,” in the physical reality, of this Ocimum Archetype. Furthermore, these species, as physical manifestations of the Ocimum Archetype, originate from a specific Biotope: they are, literally, shaped by their environment.

They are authentically orchestrated by the Terroir, the part of the Living Biosphere from which they emerge, from which they emanate – whether small or large, on the scale of a region, a country, a subcontinent…

The same applies to the Peoples of the Earth. Humanity (with a capital H) does not exist: it is merely an inept concept born of a nebulous ideology that seeks to globalize human beings into a universal melting pot. Hence the existence, for example, of the UN, the Organization for Universal Leveling – sometimes in “Gaza” mode… but not always.

It is Anthropos that exists, as an informational and genetic Archetype. And it is the Peoples, the Ethnos, the Tribes, of the Earth, that are the physical manifestations – the “sub-Archetypes in Flesh and Blood” – of this Anthropos. Just like the various species of Basilics, the various Peoples, Ethnos, and Tribes of the Earth originate from a specific Biotope: they are, literally, shaped by their environment.

The Peoples, Ethnos and Tribes of the Earth are authentically shaped by the Terroir, the part of the Living Biosphere from which they emerge and from which they emanate – with their own language, culture, mortuary practices, food and medicinal plants, rituals, culinary practices, songs, hunting, and stalking.

The aim of this essay – currently under investigation and photography – is to present a morphological guide to distinguish the various main species of Ocimum: Ocimum bisabolenum, Ocimum kilimandscharicum, Ocimum tenuiflorum, Ocimum gratissimum, Ocimum basilicum, Ocimum americanum, Ocimum carnosum/selloi et Ocimum campechianum.

This is achieved with the help of numerous photographs taken with a 100 mm Canon macro lens, which obviously has its limitations, as it is sometimes difficult for me to obtain a good photographic definition with floral organs measuring 3 to 6 mm. That being said, I am nevertheless very pleased to be able to present photographs in which the pollen grains, which are white or brick red in color, and approximately 50 microns in diameter, are clearly visible!

How to distinguish the various main species of Ocimum at first glance… or at first sniff?

Sometimes, if you are sensitive, the distinction can be made at first sniff, based on the predominant chemotype – but nevertheless in synergy with a holistic view of the plant. Thus, a low plant with a bluish aura, and a Myrrh scent, is Ocimum bisabolenum. A very tall plant with a Camphor scent is Ocimum kilimandscharicum. A fairly low plant with slender leaves, and a Camphor scent, is Ocimum americanum sp. americanum. A fairly tall plant with a Lemon scent is Ocimum americanum sp. pilosum.

How can you distinguish between the various main species of Ocimum at first glance? First and foremost, by the color of the pollen on their mature stamens, as well as the color of the anthers. Next, by the color of the flowers, the overall appearance of the plant, and the shape of the leaves, bracts, and calyxes.

White pollen grains – approximately 50 microns in diameter – on an insect visiting an *Ocimum basilicum* flower

Orange/brick red Pollen:

Ocimum bisabolenum. Secondly, this species is easily characterized by the mauve color of its entire flower, its very low and highly structured habit, and its very intense fragrance of myrrh, vanilla, and tutti-frutti.

Flower of *Ocimum bisabolenum* with Anthers and Pollen of orange/brick red color

In Ocimum bisabolenum and Ocimum kilimandscharicum, the anthers are also orange in color.

Orange/brick red pollen ball on a bee foraging on *Ocimum bisabolenum*

Ocimum kilimandscharicum. Secondly, this species is easily characterized by the white color of its flowers, its long stamens, its very unstructured habit – and, for most ecotypes distributed in the Western world, by a chemotype strongly predominant in Camphor.

Both are very hardy species that can withstand temperatures as low as 14°F ( -7°C) during the winter.

Flower *Ocimum kilimandscharicum* with Anthers and Pollen of orange/brick red color

Pollen grain, orange/brick red in color, captured by the pistil of a flower of *Ocimum kilimandscharicum*

Yellow Pollen:

Ocimum tenuiflorum. Secondly, this species is easily characterized by the pinkish-purple color and the long peduncle of its flowers, by its very loose habit and by the very crinkled shape of its leaves.

In Ocimum tenuiflorum and Ocimum gratissimum, the anthers are also yellow in color.

Flowers of *Ocimum tenuiflorum* with Anthers and Pollen of yellow color. Ecotype “Green Tulsi from Thaïlande”

Ocimum gratissimum. Secondly, this species is easily characterized by the green-yellow-brown color of its flowers, by its very broad leaves, and by its very tall, upright plants.

Both species require a lot of heat, and in certain regions, it is advisable to grow them in a greenhouse.

Flowers of *Ocimum gratissimum* with Anthers and Pollen of yellow color. Ecotype “Mtulé”

White Pollen:

Ocimum basilicum. Specifically, some cultivars, but not all, are easily characterized by the crinkled and ruffled shape of their leaves. (“Mammoth”, “Napoletano” et “Laitue”); by the very purple color of their leaves (“Purple Rubin”, “Osmin”, “Rosie”, “Purple Ruffles”, etc); by the globular shape of their plants (“Grec”, “Floral White Spires”); by very small leaves (“Grec”, “Latino”); by floral clusters with very dense cymes (“Cardinal”).

It is sometimes difficult to distinguish between Ocimum basilicum and Ocimum americanum. Using a macro lens, it is possible to see that their calyxes and bracts are quite different.

Ocimum americanum. Specifically, some cultivars, but not all, are easily characterized by the small size of their flowers in Ocimum americanum sp. americanum; by a chemotype predominantly containing Citral in Ocimum americanum sp. pilosum; by a chemotype predominantly containing Camphor in Ocimum americanum sp. americanum.

White Pollen of *Ocimum americanum* var. pilosum – ecotype “Esfahan” from Iran (USDA PI 253157).

In Ocimum basilicum and Ocimum americanum, the anthers are also white or creamy white in color.

Ocimum carnosum/selloi. Secondly, this species is easily characterized by the shape of its flowers – in particular, the bract – by the shape of its leaves, by the brown color of its anthers… and by its overall appearance.

White Pollen of *Ocimum* *carnosum/selloi*

Ocimum campechianum. Secondly, this species is easily characterized by the difficulty of seeing its tiny flower in the center of the calyx, by the reddish color of its anthers, by the shape of its leaves, by the shape of its bract… and by its overall appearance.

White pollen on the pistil of *Ocimum* *campechianum*

**How can Ocimum bisabolenum and Ocimum americanum be distinguished specifically by the morphology of their flower stems?**

Caveat. The purpose of this section is to highlight, based on the morphology of their respective flower stems, that there is no possibility of asserting, as some botanists still do, that the temperate Tulsi, the Ethiopian Besobila – which I have named Ocimum bisabolenum – could be Ocimum americanum… and even less so Ocimum americanum var. pilosum.

This is in addition to characteristics specific to Ocimum bisabolenum, namely: orange pollen and anthers; entirely mauve flowers; a scent of myrrh, vanilla, and tutti frutti; and a very low, highly structured growth habit.

Ocimum bisabolenum grows to an average height of 35 to 40 cm in the garden. However, it can easily reach 55 cm in width, especially since this species of Ocimum is very adept at occupying all the space available to it. In a well-watered pot, the plants can reach 50 cm in height but, above all, spread very generously downward.

There is no diversity in terms of shape, color of flowers, or pollen in the various ecotypes of Ocimum bisabolenum that have been commercially available since 1955 – at least, those that I am familiar with. The only variation I have noticed, to date, concerns the color of their leaves: some plants are a much lighter shade of green.

The flower stems are, on average, 10 to 12 cm long and can reach up to 18 cm. As for the dry bracts, the largest are about 4 mm wide.

Dry Bracts, 4 mm in width, in Ocimum bisabolenum

The interval between the “cymes” (6 flowers simulating a whorl around the stem) is very small. Thus, there are 21 cymes on an 18 cm floral stem – i.e. with an average interval of 8.5 mm.

There are thus twice as many cymes in Ocimum bisabolenum as in Ocimum americanum var. pilosum – for the same length of flower stalk.

In addition, the bracts of Ocimum bisabolenum are much hairier. When dry, the largest ones are 4 mm wide, while those of Ocimum americanum var. pilosum are 5.5 mm wide and those of Ocimum americanum var. americanum are 3 mm wide.

Center: *Ocimum bisabolenum*. Left: *Ocimum americanum var. pilosum*. Right: *Ocimum americanum var. americanum.*

Ocimum americanum var. pilosum – namely the different ecotypes that I have grown this year – are, on average, approximately 50 to 85 cm tall in the garden.

These are the following ecotypes: “Kali”, “Mrs. Burns”, “Sweet Dani”, Lime Thai”, “Anis” (Richters Seeds), “Nouvelle Guinée” (Kokopelli) and the Turkish ecotype of Lemon Basil, “Esfahan, PI 253157”.

The flower stems are, on average, 20 to 30 cm long in “Sweet Dani” and 17 to 30 cm long in “Esfahan. PI 253157.” As for the dry bracts, the largest are approximately 5.5 mm wide.

I recall that this year, the tallest Basil stems I measured, in the garden, were 36 cm long in “Esfahan.” This record was broken, on the balcony, by a crossed Ocimum kilimandscharicum, Kapura X. SP. 01/2025, which grew to a length of 38 cm.

Dry Bracts in *Ocimum americanum* var. pilosum – ecotype “Esfahan” from Iran (USDA PI 253157).

The interval between the “cymes” (6 flowers simulating a whorl around the stem) is relatively large. Thus, there are 11 cymes on an 18 cm floral stem in Lemon Basil – with an average interval of 16.5 mm.

It should be noted that this inter-cyme interval, of 16.5 mm, is virtually identical for the ecotypes “Kali,” “Mrs. Burns,” “Sweet Dani,” and “Lime Thai” – regardless of plant size. However, it is much smaller in the purple ecotypes of Ocimum americanum var. pilosum – “Anis” (Richters Seeds) and “Nouvelle Guinée” (Kokopelli).

Ocimum americanum var. americanum – namely the different ecotypes that I have grown this year and in 2022 – are approximately 35 to 55 cm tall in the garden.

These are the following ecotypes: “Malawi Camphor”, “African” (Kokopelli) as well as various ecotypes, from GRIN, originating in Zambia, with a chemotype Camphor or Eucalyptol.

The flower stems are, on average, 18 to 20 cm long in “Malawi Camphor” and other Zambian ecotypes. As for the dry bracts, the largest are about 3.5 mm wide- and are therefore smaller than those of Ocimum bisabolenum.

Dry Bracts in *Ocimum americanum* var. *americanum*. Ecotype “Malawi Camphor”

The interval between the “cymes” (6 flowers simulating a whorl around the stem) is very small. Thus, there are up to 35 cymes on a 21 cm floral stem in Zambian Camphor basil – with an average interval of 6 mm.