Botany Out of Season

A lecturer could arrange a botany course by plant families. The plants themselves flowered in a different order. In Breslau in the early 1860s, Ferdinand Julius Cohn found this a serious obstacle: the examples needed for a systematic explanation would not necessarily be in bloom, and in winter many would be unavailable altogether.

Even a flower delivered on time might be too small. Students had to distinguish the arrangement of its organs before those differences could help them recognise a family. A pressed specimen flattened the relationships Cohn wanted to explain. A description could name them without making them visible.

The solution began with a pharmacist, Carl Leopold Lohmeyer, who made flowers large enough to teach from. Within a few years Robert Brendel was offering copies for sale. The painted plants on their wooden stands would travel far beyond the classroom that had prompted them.

A botanist, a pharmacist and two cupboards

Cohn taught at the university in Breslau, now Wrocław in Poland. He wanted students to encounter plants through living material, experiments and demonstrations. Lohmeyer, an amateur botanist as well as a pharmacist, began constructing his enlarged teaching specimens around 1862 at Cohn’s suggestion.

Wood and cork provided the framework. Card covered in coloured paper became the leaf-like organs. Where the exterior concealed the arrangement within, Lohmeyer made parts detachable. A lecturer could remove an obstruction while keeping the rest of the plant available for comparison.

By 1864 Lohmeyer had made about two hundred models.

They occupied two cupboards in the university auditorium, where their appetite for space attracted objections. In early 1866, on Cohn’s advice, Lohmeyer gave the collection to the university. Housing the gift became the institution’s problem. Cohn eventually obtained rooms in the former St Joseph’s college, the Steffenshaus, for a plant-physiology institute. The objects had helped create a demand for the rooms in which they could be used.

Other institutions wanted equivalents. Robert Brendel, already a manufacturer of rubber and gutta-perchaGutta-percha×A tough, rubber-like material obtained from the milky sap of certain Southeast Asian trees.Merriam-Webster · gutta-percha ↗ goods in Breslau, recognised a business. In 1866 he advertised a first series of thirty flower models for twenty thalers, excluding packing. He acknowledged Lohmeyer’s originals and Cohn’s part in their development. Each copy would carry the plant’s name, its classification and its enlargement ratio.

The advertised objects were painted in oil, varnished and mounted on polished wooden stands. Some could be taken apart to reveal their internal organs. Disassembly was a feature chosen for particular lessons, rather than a property of every plant Brendel sold.

Credit became contentious. Lohmeyer’s son Julius wanted the copies marked as derived from his father’s work. In a letter of April 1867, reproduced in later scholarship, Cohn responded that Julius could put the name on the boxes himself. The manufacturer’s name became the one by which the objects travelled.

There is also a less comfortable history behind their construction. Historian Matthias Svojtka, drawing on Hans-Joachim Klemm’s research, identifies Brendel’s early inexpensive labour force as prisoners in Breslau, trained to form, paint and press the components. The polished teaching aids emerged from a working arrangement largely invisible on their labels.

Paper that held its shape

Manufacturing copies required a form that could be repeated. Moulds supplied matching components; finishing still involved handwork. The same flower could be produced for several customers without being modelled afresh for each one.

Conservation research on the Brendel collection in Madrid reveals the combination of materials. Papier-mâché formed petals, leaves, pods and anthers. Internal wires acted like ribs, holding thin structures in an open shape. A white preparation covered the paper surface before colours were applied by hand in an oil-based medium. Small metal hooks joined some of the removable parts.

The materials changed with the structure being represented. Cotton, silk, feathers, plaster, wood, fibres and gelatin all had uses. A rigid support might hold the whole object upright while a finer material supplied a delicate organ. The turned base carried the model and its printed identity; the botanical form above it combined several kinds of work.

An enlarged pea pod makes the practical arrangement easy to follow. Closed, it preserves the outline of the fruit. Opened, it places the seeds and their attachment inside a cavity large enough to inspect. The halves can be brought together again, so the explanation can move between whole and interior without destroying the specimen.

A closer look · 1:01 · No spoken commentary

A flower in the round

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The roots that pointed upwards

A model could combine useful views, but the arrangement could also mislead. An early Brendel meadow saffron, Colchicum autumnale, preserved in Vienna stands about 43 centimetres high. Its flower is displayed with its underground structure. The roots point upwards.

The underground part could be lifted off its support, but the orientation was awkward for an object intended to clarify how a plant was built. A later Berlin version corrected the roots to point downwards and made that part dismantlable. The alteration survives in the objects themselves: the teaching design was revised along with the product.

The living plant explains why such a construction was useful in the first place. Meadow saffron sends up its pink-lilac flowers in autumn. Its broad leaves appear in spring and die back before the next flowering. A teacher wanting to relate the bloom to the rest of the plant could not simply wait for everything to appear together.

A botanical plate could bring separate views and stages onto one page. The model offered a different operation: a teacher could turn it, point into it or remove a part. Both selected information from the plant. Brendel’s first arrangement of the roots shows how much depended on the selection being sensible.

A transparent spore case

Some of the most ambitious models concerned structures far smaller than a conspicuous flower. Ferns produce spores in tiny cases called sporangia. Brendel enlarged one from Pteris serrulata into an object whose outer wall could be opened, exposing the contents while retaining the outline of the closed case.

Gelatin could supply a translucent surface that opaque paper could not. It was also vulnerable. A particularly elaborate moss capsule, introduced in 1885, combined gelatin with wood, wire and varnish. Enlarged 150 times, the capsule of Brachythecium rutabulum originally separated into six principal elements, including its cap, lid, ring and central column.

The miniature structure became a substantial piece of apparatus. The Vienna example measures 44 centimetres high and 41 centimetres long. It cost fifty marks in 1885, against nine to eighteen for an ordinary flower model. For the moss capsule and another difficult model showing the feeding organs of parasitic dodder, Brendel asked buyers to allow two to three months for delivery.

Ordering a classroom garden

Robert moved the business to Berlin in 1873. His son Reinhold took over its management in 1889, and by 1897 the firm had premises in Grunewald. Its catalogues offered much more than flowers: germination, crop plants, fungi, microscopic structures and insect-catching organs could all become teaching objects.

New research could enter the range. Emerich Ráthay, a botanist specialising in viticulture, investigated the sexual forms of wild and cultivated grapevines. In 1890 five new Brendel models presented those findings in three dimensions. Other scientific collaborators advised on flower arrangements, ovules and the positioning of leaves.

The catalogue let a distant teacher order a particular operation.

The 1900–1901 list describes an eighteen-times enlarged cacao flower with removable components, a tulip with three detachable floral leaves and a pistil that comes apart, and a wheat-grain section enlarged fifty times. It states scales and prices alongside the parts that could be lifted out. The buyer could choose what a class needed to see.

In Madrid, the purchase left a detailed paper trail. In 1912 the Universidad Central acquired the collection of 196 Brendel models now held by Complutense University, for its Laboratory of Descriptive Botany under professor Blas Lázaro Ibiza. A Casa Torrecilla invoice records freight from Grunewald to Irún, onward transport to Madrid, delivery to the Faculty of Pharmacy and agency expenses. The account totalled 4,610.10 pesetas and carried Lázaro Ibiza’s approval.

When the real flower was enough

The models had critics among the people expected to use them. Writing in 1910, Hamburg teacher Johannes Suhr accepted their value when fresh material was unavailable, too small to see or difficult to dissect. He nevertheless considered most of Brendel’s flower models unnecessary for his teaching, however well made they were.

Suhr made an exception for the rye spikelet.

Its small, closely packed parts offered a clear reason to enlarge and separate them. He also recommended models of the tiny sexual stages of certain spore-producing plants. His choices brought the argument back to the difficulty Cohn had faced: the expense was easiest to justify when the living object could not readily explain itself to a class.

Survival introduced another problem. The objects had to withstand handling, but their fine components and joints could wear or break. Conservators in Florence found models neglected in a damp basement, with original documentation lost. In Madrid, researchers recorded cracked paint, exposed paper, corroded fittings and detachable parts that no longer sat correctly.

For the Madrid restoration project, digital scanning and photography allowed conservators to test the positions of detached elements before moving the originals.

On the physical objects, they filled vulnerable losses with layers of shredded Japanese paper and adhesive, secured unstable paint and retouched selected gaps. The watercolours used for retouching were diluted in ethanol, limiting the amount of moisture introduced during treatment.