388 i Flora Unveiled
amicably with the younger Linnaeus and had given him encouragement. In 1732, Heister
and his seventeen- year- old son, Friedrich, published a dissertation touting a new method for
assigning plant genera based on leaf morphology. Linnaeus apparently regarded Heister’s
method as archaic and idiosyncratic, although the subject never came up in their corre-
spondence. In the first edition of Systema Naturae (1735), however, he listed all the botanists
who had used fructification as the basis for classification, singling out Heister as the lone
exception. In the same year, he published a short history of botany in which he pronounced
Heister’s method a mere “draft,” and, in a table of taxonomists, he grouped Heister among
the “heterodoxi.” Heister was deeply offended, and he struck back by publishing a paper
rejecting Linnaeus’s sexual system as completely worthless.^22
Siegesbeck remained loyal to Heister, and it seems likely that he nursed a grudge against
Linnaeus for insulting his former mentor. This would explain why, after a series of friendly
letters between Siegesbeck and Linnaeus that also involved exchanges of plant material,
Siegesbeck suddenly launched his Jeremiad against the sexual system. As farcical as the events
now seem, Linnaeus suffered serious mental anguish over the dust- up and never forgave his
Prussian nemesis. He found it particularly galling that Siegesbeck had attacked Systema
Naturae mainly on theological grounds, a domain that Linnaeus, a minister’s son who
believed that his reform of botany was sanctioned by God, considered to be his unique calling.
In none of the preliminary letters he had exchanged with Linnaeus did Siegesbeck ever hint
that an attack was imminent, but Linnaeus got wind of it through his Russian contact, Johann
Amman, Professor of Botany in St. Petersburg.^23 Amman warned Linnaeus that Siegesbeck
was preparing an extremely harsh critique of the sexual system. Linneaus, who was then liv-
ing in the Netherlands and working on a description of the gardens of his wealthy patron,
George Clifford, decided on a pre- emptive strike. In keeping with his taxonomic rule that
there should be an organic link between a plant and the botanist after whom it was named,
Linnaeus quickly gave the name Siegesbeckia orientalis to a small weedy composite with an
unpleasant odor and published it in Hortus Cliffortianus in the summer of 1737.^24
In December 1737, Siegesbeck published his anticipated blast, innocuously titled A clear
evaluation: Linnaeus’s recently published sexual system of plants, and his method for organiz-
ing the superstructure of botany.^25 Siegesbeck began by arguing that according to the Bible,
God created plants on the third day, and he did not start with seeds. Rather he created
plants fully formed, with their flowers, fruits, and seeds present from the start. There is
no mention in the Bible of the existence of two sexes in plants or of sex being required for
seed formation. The seed is an integral part of the vegetative plant— a vegetative propagule.
And although it was true that Ray, Camerarius, and Vaillant had demonstrated something
resembling sex in plants, this still did not justify describing stamens and pistils as male and
female organs. Alternative explanations had not been ruled out. In other words, Siegesbeck
challenged the legitimacy of the sexual theory upon which Linnaeus had based his entire
system of classification.
However, Siegesbeck’s primary argument against the Linnaean system was its shocking
immorality:
For what strange, discordant orders and classes, totally contrary to Nature, is it not
necessary to subordinate in such a Method because of this fictitious matrimony of
plants, e.g. when eight, nine, ten, twelve, even twenty or more husbands are found
here in the same [bridal] chamber together with one woman.^26