In Germany, in 1933, due to increased pressure by the Hitler regime, especially on the Jewish people, in order to isolate them from society, the process of escaping from Germany began. The first stop, especially for the academical refugees, was The Society for Assistance to German Scientists Abroad in Zurich which was led by Prof. Dr. Philipp Schwartz. Because of the hospitality displayed by the Turkish institutions "mass immigration" of German academicians occurred. Thus, Istanbul University became "the greatest and the best German university". This experience turned out to be successful by employing the help of students, assistants and voluntary translators who helped overcome the problem of language.
When a University Reform was made in Turkey the same year in August, many worthy and famous scientists of German origin taking refuge in Switzerland came to Istanbul, in October, upon the invitation of President Mustafa Kemal ATATÜRK and became members of various faculties of Istanbul University. While Ord. Prof. Dr. Alfred HEILBRONN gave lectures in the Pharmacobotany and Genetics Institute in the newly built Biology Building in Süleymaniye, which was called Biology Institutes at that time, together with his colleague and friend in destiny Ord. Prof. Dr. Leo BRAUNER he worked on the establishment of the most modern Botanical Garden in Turkey after the declaration of the Republic.
Within the Botany Department of the Biology Institutes in Süleymaniye, there were two Institutes (which will later be called Chair). These were the "Pharmacobotany and Genetics Institute" and "General Botany Institute" directed by Ord. Prof. Dr. Alfred HEILBRONN and by Ord. Prof. Dr. Leo BRAUNER, respectively. In the years following the University Reform, these Institutes made progress in education and research in the fields of "Pharmaceutical Botany", "Genetics" and "Plant Physiology"; and later due to an increase in the staff and efforts lectures and research in "Plant Morphology", "Plant Systematics", "Ecology", "Algology" and "Paleobotany" fields started. Moreover, the staff of this institute lectured to the Medicine, Pharmacy, Dentistry, Forestry and Veterinary Faculties' students on PCB (Physics, Chemistry, Biology) in General Botany classes and laboratories. Previously, Plant Physiology and Plant Systematics courses were given in General Botany Institute by Ord. Prof. Dr. Leo BRAUNER and institute staff. Since 1965, the Plant Systematics classes were taken over by Botany and Genetics Chair staff.
According to information compiled from various sources, the academicians who worked in the Botany Institute under Ord. Prof. Dr. Alfred HEILBRONN were: Sara Akdİk, Mehpare Başarman (Heilbronn since 1948), Nebahat Yakar, Fevzi Öztığ, Recep Egemen, Jale Tören, Fahire Yenal, Nevin Elgin (Özkan), Fatma Sayı, Hüsnü Demiriz, R. Okay (Ülgen), Sehavet Atay (Okyar), Emine Bilge, Betül Tutel, Ayhan Soyerman (Koçak), Perihan Acarer (Oraler), Bilgin Tözün and Ayten Aydın. The garden's technical personnel were Adnan Mete, Ahmet AtİLla and plant artist Maryam Agavni Ertoran. The courses given by Ord. Prof. Dr. Alfred HEILBRONN were: Plant Biology, Genetics, Pharmacobotany, Plant Anatomy (to Pharmacy Faculty students) and Pharmacognosy. Ord. Prof. Dr. Alfred HEILBRONN started collecting Turkish herbs, especially ones with medical properties, as herbarium material, while he taught the hybridization studies of plants and chromosome examination methods to the young assistants in the Pharmacobotany and Genetics Institute.
Even though he was a physiologist, Ord. Prof. Dr. Leo BRAUNER also lectured on Plant Systematics (Cryptogame and Phanerogame) and Plant Physiology and he assigned to the students he raised lecturing on Plant Morphology and Plant Anatomy. Although he was not a plant taxonomist, to meet his students' needs, after a long and tiresome study, he wrote with great sacrifice two books Cryptogame and Phanerogame which are considered as masterpieces of their time and are still used today. Brauner organized seminars with his assistants and students and always supported those who wanted to do research.
Ord. Prof. Dr. Alfred HEILBRONN had the idea of establishing a botanical garden in Istanbul University ever since he had started lecturing in Istanbul. He explained his ideas on having a botanical garden resembling the ones in Europe and founding a Biology Institute in an interview that was made later as follows:
"When I came to Istanbul, I found myself in front of an institute which had only three rooms and was in a decrepit condition. I had to give lectures to about 1000 students in Zeynep Hanım's hippodrome (Zeynep Hanım Konağı (Mansion) in Vezneciler which was the first building used by the Faculty of Science). The government accepted the impossibility of such a situation and gave me the permission to establish a new institute and arrange a botanical garden in place of the small garden with 90 plants. The new institute's plan was prepared by architect Prof. Dr. A. EGLI, where Prof. Dr. Andre NAVILLE, Ord. Prof. Dr. Leo BRAUNER and I acted as consultants. The ministry had a perfect building constructed by 1937, exactly according to those plans."
The construction of the garden was started prior to that of the building's and following the first arrangements in 1934, it began operating in the spring of 1935 under the name of İ. Ü. Botanik Bahçesi (I. U. Botanical Garden - Hortus Botanicus Istanbulensis). Ord. Prof. Dr. Alfred HEILBRONN worked hard, so that the botanical garden has similar conditions to its advanced counterparts in Europe; he corresponded personally with Germany's leading corporations of the time in order to buy long-lasting and high-quality equipment and he also contributed to the drawing of the garden plan and greenhouse projects. The botanical garden was established with contributions from Ord. Prof. Dr. Leo BRAUNER who supported Heilbronn vastly in the arranging of the garden and in education along with garden curators (Horti Inspector) W. STEPHAN, G. A. CATT, G. A. M. PISARD and H. LÜCKE and chief gardeners (Hortulanus Primarius) Adnan METE and Ahmet ATİLLA. The garden curators were selected from a group of educated people who are knowledgeable about theoretical and practical issues in gardening.
Among these curators, English G. A. CATT and Ahmet ATİLLA, who received professional and botany education in Bursa School of Agriculture, Gardening Branch, published articles in various periodicals on gardening techniques and plants. In 1935, the first seed catalogue of the botanical garden was published under the name of "Istanbul University Botanical Garden Seed Catalogue" (Index Seminum Hortus Botanicus Istanbulensis). One important feature of the seed catalogues was that the cover generally included pictures of plants from Turkey's flora some of which were endemic ones. These realistic and scientific pictures were drawn by botanist academic member Assoc. Prof. Nebahat YAKAR and plant artist Maryam Agavni Ertoran.