Of the fifty-four individuals publicly honored in the Jardin des Plantes, how many are women?

Two. Anne Vasermanis and Deborah Lifchitz.

The Jardin des Plantes, Paris’ four hundred year old home to some of the West's first scientific steps in ecology, botany and zoology upholds a key tenet of all scholarly institutions; label everything. Visitors will be hard pressed to find an unnamed tree, flower or shrub, though they may be impressed by the fact that even the rocks get identity tags. 
And there is a zoo. 
Amid the cacophony of categorization, fifty two dead white men are also named. Often honored in statue form, many of these early naturalists are depicted in busts mounted on various museums and buildings of the park. 

The vast majority of the men honored in the Jardin worked during the Enlightenment when Paris started the path to a more secular and rational western civilization. With eight separate dedications, Count Buffon, who wrote many of the first encyclopedic descriptions of the natural world, leads the pack of the park’s honorees. Also publicly recognized are Jean-Baptiste Lamark who promoted a theory of evolution before and not too far removed from Darwin’s, Antoine Laurent de Jussieu an early botanist, Georges Cuvier who founded comparative anatomy and dozens of other great but dead white men.

Three of the honored naturalists at the Jardin.

Among the portraits and plaques are allegorical renditions of Mother Nature, muses of learning, anatomically correct wild animals including dinosaurs, a hippo, a pelican, several crocodiles and so on. In two places; by the Seine entrance to the park and on the side of the Cabinet d’Histoire building are tablets  honoring war dead associated with the Jardin. One marble tablet includes a dedication to the 1944 “fallen heroes of the Liberation” given by “neighbors and communist resistance cells”. The word “communist” has been scratched out showing that in Paris, old animosities stay fresh.

On the outside wall of the Cabinet d’Histoire, the Garden’s history museum, are two marble plaques, one above the other simply listing the seventeen staff members who died during WWI and WWII. Two of the dead, Vasermanis and Lifchitz, were Jewish women rounded up in Paris and sent to die in the Holocaust camps to the east.
Honoring France's war dead, these plaques recognize those "who died on the field of honor."
Deborah Lifchitz was not a practicing Jew. She did not attend services on a regular basis.  Her boyfriend, the father of her child, did not wear a yarmulke, and her son was probably not circumcised.[1]  She was more than a bit non-conformist for the 1930’s in general and not simply for her religion or lack there-of. As one of the first professionally trained female ethnologists, Lifchitz worked as a trailblazer in a fledgling field, but one dominated by men and old-school ideas about race and gender.

In 1935, she managed to take part in a research trip to the French colony of Mali.  Focusing on the native Dogon language and oral traditions, Lifchitz wrote three pioneering studies during that trip and was part of an intellectual circle still cited by anthropologists today. From Mali, she brought back two museum worthy pieces of Dogon art currently displayed in the Louvre and the Quai Branly museums.

Lifchitz'sstatue in the Louvre today. 

The only women publicly mentioned at the Jardin.
Lifchitz died in a gas chamber at Auschwitz aged 35.

Little is known of Anne Vasermanis. 

[1] Deotte, Martine. “Les hommes de bonne volonte” in Etudes sur Roger Bastide. Ed. Claude Ravelet. L'Harmattan: Paris. 2003. p. 26 http://books.google.fr/books?id=Fk6V8aUKP1sC&pg=RA1-PA25&lpg=RA1