Hortus Malabaricus (The Garden of Malabar) is a 17th-century botanical documentation on the medicinal properties of flora of the Malabar coast, a coastal region of Arabian sea, mostly coming under the Indian state of Kerala and a part of Western Ghats bio diversity). It was compiled by Hendrik van Rheede, the Governor of Dutch Malabar from 1669 to 1676.He has also used the Ayurveda knowledge of Itty Achuthan, a traditional medicine healer who practice Ayurveda through his family tradition and 3 Kongini Bramins who were also a part of the team in identifying and describing the plants to the documentation experts of Van Rheede.

As an excellent military strategist Van Rheede knew that Ayurveda has the potential to keep the Dutch soldiers and officers healthy in unfamiliar climate of tropical India, which in turn gives a better military advantage to Dutch East India company, But the publication of Hortus Malabaricus was intended to find market and monopoly for Herbal medicines in to Europe, it is also noted that many tropical medicinal herbs have European names which is connected to the healing traditions and practices  of Europe.  Van Rheede was personally involved in this project and he collected the information in a very systematic way, Itti Achuthan who disclosed the Ayurvedic and traditional medicine knowledge about the plants of Malabar to him. Hortus Malabaricus was published in Amsterdam between 1678 and 1693. Unfortunately, after the death Van Rheede, the book was preserved in few libraries in the world and after 300 years English and Malayalam translations of Hortus Malabaricus were published by University of Kerala. Professor K. S. Manilal, a Botanist was the only reason behind it who spend 3 decades of his academic life behind the revival and translation of this book from Latin to English. Professor K. S. Manilal, an Emeritus of the University of Calicut, Kerala has devoted 35 years of his life to research for the translation and annotation work of the original text of Hortus Malabaricus and learned Latin language and translated all the contents.

Richard H. Grove, in his book 'Green Imperialism: Colonial Expansion, Tropical Island Edens and the Origins', states that Itty Achuthan and his team selected the plants to be drawn and included in Hortus Malabaricus, with traditional morphological information and identification details such as mentioning of vernacular (local) name of the plants. Medicinal properties of these plants were known also to the Dutch through their experience with local healers who were also practicing the Ayurveda. The codified information in the Sanskrit and Malayalam were available at that time as most of the Ayurvedic practitioners were coming though the tradition of Ashtanga Hridayam an Ayurveda text book originated in AD 700 under the Buddhist tradition of Ayurveda at that time. We could still see the same information is taught in the Medical universities of India for Ayurveda Students under their curriculum. As the main informant Itty Achuthan dictated the material in Malayalam and Sanskrit languages, which was then translated into Portuguese then Dutch and finally into Latin. Three other Ayurvedics scholars who participated in this project were Ranga Bhat and Vinayaka Pandit Appu Bhat, Hortus Malabaricus was compiled over a period of nearly 30 years as the volume of information was so huge. Ayurvedic system in Kerala use more than 2000 plant species for their medical practice and it was a huge challenge for the Van Rheede and team so they have selected the plants not only for their medical properties but also for their economic point of view as crops and trade importance.  Hortus Malabaricum is published in Amsterdam during 1678–1693. 

Involvement of Itti Achuthan was also significant because of the “Ezhava caste” he belongs to. The high caste Brahmins were supposed to be traditional authorities of Ayurveda and all other Vedic knowledge at that time due the restrictions and discrimination of  caste based society in Kerala. Probably for the high caste Brahmin healers, mingling with Dutch nationals  were unthinkable even though they were the colonial rulers, and may be Van Rheede also wanted to avoid such situations and choose Itti Achuthan who was willing to share the knowledge and highly regarded for his Ayurveda skills at par with Bramical tradition of Ayurveda.  It is also interesting to say that Kerala had diverse Ayurveda practitioners from different castes and social back grounds, Van Rheede found that as all of them were coming from the textual tradition of Ashtanga hridyam (AD 700) they all share the similar knowledge. Even though the Ashtanga Hridyam was considered as text book from Buddhist period it follows the same lineage of information as in the compilation of Charka Samhitha and Susrutha Samhitha which was purely originated under the Vedic tradition of India before the Christ. It was wrongly noted in many reference that there was Ezhava healing traditions in Kerala by some historians who has wrongly understood the textual Ayurveda traditions in Kerala.

Informants collected the plants from their natural habitat and codified the information from different text books which was in practice at that time and also through discussion and debates which in turn created the most authentic data available at that time Rheede himself wrote about his wonderful experience: "I have often witnessed a most delicious conversation when, for instance, these philosophers argued and discussed with each other with the weight of arguments, verses from antiquity and books of their teachers, which stand for their learning. They argued and defended their own opinions, but with an incredible modesty, such as is lacking even in the most eminent philosophers of the world, without any harshness, mental restlessness or neglect of respect for the opinion of the other. They revere antiquity and the first inventors of their sciences with the most pious reverence, and by them they judge their own opinions and also their own experiences, and submit them to their authority. And as for medicine and botany, (Ayurveda) the knowledge of these sciences is recorded in verses, the first line of which begins with the proper name of the plant, its species, properties, forms, parts of plants, location, season, medicinal benefits, and the kind, which they then describe in great detail. They did this so skilfully that when someone named the proper name of a plant, everyone else would immediately respond and recite whatever had been and could be said about it. Although this method of teaching, which requires a persistent memory, seems to be quite difficult, these verses imprint themselves with playful ease on the minds of the students, who are said to memorize them most easily. Later they were pre-served in the minds of scholars till they die. According to Van Rheede, "the first mentions of these disciplines of medicine and botany (Ayurveda) are considered to be as old as they are presented in the books by the authors mentioned, and according to them are thus four thousand years old." Probably Rheede was referring the text books and the medical treatises of Charaka, Susruta and Vagbhata.

Itty Achuden stated in his source notes in the first volume of the book that the information on the healing powers of plants was taken from his books on Ayurveda, especially the Ashtanga Hridaya, which was widely used by Ayurvedic practitioners in Kerala. Other Ayurvedic textbooks of regional origin are also used in this work, In this work, three Konkani Ayurvedic doctors played an important role in documenting the knowledge they had re-ceived from various local healers. Even today, many authentic Ayurvedic textbooks lack detailed descriptions and illustrations, due in part to the fact that this knowledge was only passed on orally, and students learn the knowledge of medicinal plants only from their teacher, rather than from other sources. Many scholars worked for years in Kerala and in Amsterdam for perfecting this gigantic work. A scholars’ team including Itti Achudan has been moved to Amsterdam to aid the editing works. Finally, the Hortus Malabaricus which describes about 780 species of the most important Ayurvedic Medicinal plants of Malabar with the fine accuracy for any botanical illustration and details, supported by 794 unusually beautiful illustrations printed with engraved copper plates, each plants have description in Latin and its name in four languages was published from Amsterdam.

Van Rheede's contribution is the only source of illustrative reference point to the extensive knowledge of Ayurveda in the world. The Hortus Malabaricus was first published in the 17th century and was promoted by scholars of Europe as a milestone in plant science.  It took 75 years for the official botanical nomenclature to develop during the interventions of Carl Linnaeus and the renaissance of botanical science. He has repeatedly mentioned the detailed morphological description of plants and the technical illustrations in in Hortus Malabaricus and Van Rheede's contribution. The Hortus Malabaricus contributed to the identification of 250 new plant species and was mentioned by many classical botanists in their works. Adenson (1763), Jussieau (1789), Dennstedt (1818), Hasskarl (1867). Several other later botanists who also used the Hortus Malabaricus to name new species, treating the diagrams in the book as real and oroginal since no original herbarium specimens of these plants are available. The importance of the book Hortus Malabaricus, which contains detailed illustrations of plants used as medicine and food, and their medicinal properties are evidence of the practice of Ayuvedic herbs in Europe at this time. And the contribution of Hendrik Adriaan Van Rheede in the greatest ever herbal medicine pharmacopeia of the east.