The 19^th century was marked by an increased interest in the connection between climate and plant distribution. Together with the ever-growing trade routes between the East, the West and the Americas, which also moved plants such as ferns from one corner to the other of the globe, also grew scientific interest in the dispersal and distribution of plants and organisms around the world. Factors like temperature, soil water and light started to inform a multilayered discourse on ecology. 

Beautiful Wild Flowers of America (1882) combines original water-colour drawings by Isaac Sprague with descriptive texts by Reverend Hervey. The illustrations of fringed gentian, wild columbine, mountain fringe, wild clematis, swamp rose, moccasin flower and long-leaved aster are accompanied by poems and texts. The emphasis is on the beauty of flowers as gifts of God and as integral parts of the book of nature.

British Eocene Flora was prompted by the discovery of fossil leaves in Bournemouth. Baron Constantin von Ettingshausen and John Starkie Gardner carried out a comparative study of British, American and Australian fossils. By focusing especially on the Bagshot Period, that is, the time in history when from sands and clays of shallow-water origin, basins such the London and Hampshire ones were formed, the authors were able to advance speculations about the land connection between Europe and North America. The leaf-bearing clays of Alum Bay and Bournemouth, which Gardner and Ettingshausen studied yielded a large series of plant remains, which they illustrated in their book. An attempt at facilitating the recognition of plants was made thorough drawing, for venation and texture were regarded as sufficient indicators of a plant’s look. About 55 million years ago temperatures around the globe spiked. Sea levels rose and oceans became more acidic, some species became extinct. This event, known as the “Paleocene-Eocene Thermal Maximum” (PETM) is a potentially useful source of information to gather data with respect to our current conditions. It seems that PETM was caused by greenhouse gases.

Constantin von Ettingshausen also wrote Blatt-Skelete der Dikotyledonen (1861). The Austrian botanist conducted his palaeobotanical studies of flora from the Tertiary era. He arranged the collection of the Natural History Museum in London and conducted research on fossil floras of Australia and New Zealand. Dicotyledons or dicots are one of the two groups into which all the flowering plants were formerly divided. The peculiarity is that the seed of such plants has two embryonic leaves instead of one alone.

Agricultural Grasses of the United States (1884) moves from the belief that every thoughtful farmer must take care of grass supplies for pasturage and hay. The question the author wants to answer is whether specific kinds of grasses that grow in certain parts of the country can be cultivated elsewhere, where they are not yet available. Grasses from several American countries are taken into account together with their peculiarities, advantages and suitability to local industries and culture, like winter grazing in the Rocky Mountain region. Peculiar about the book is that in order to show the entirety of the grasses, they have been folded to fit the page.

Genesi, organizzazione e metamorfosi degli infusori was published posthomously after the death of Egisto Tortori in 1893. Tortori was appointed director to the Institute of Natural History in Florence. As a pupil of the former director of the institute, Luigi Calamai, Tortori was skilled in the production of standards illustrating flowers, plants, anatomical parts and microorganisms on hemp fabric in a bath of black wax. Art and science fuse in Tortori’s works by producing alternatives to the wax sculptures which he had produced in the former part of his life. In the Long 19^th century, wax sculpture gained popularity in the fields of phrenology and physiognomy. Being commissioned by the Calamai to produce illustrations of botanical and zoological subjects for teaching, Tortori developed an interest in minor species, which he pursued independently and produced 60 illustrated folia over seven years. His aim was to verify whether species in nature and their counterparts in vitro underwent the same growth. He went on to nourish the microbes with water every day and verified that their growth was steady as that of creatures living in the wild. The pictures illustrating his book endorse Tortori’s theory that nature, although infinitely varied, aims at the sole reciprocal assimilation of organisms via germs.