This genus is a member of the family Euphorbiaceae. You may be familiar with Cassava (Manihot esculenta), a plant that is commonly cultivated for it starchy root in tropical and subtropical regions of the world; when dried and ground, it is referred to as tapioca. The exquisite palmately lobed leaves in this genus are featured below.
Veit B. Wittrock of Stockholm, Sweden created this four-volume collection, called an Exsiccatae. An Exsiccatae is a bound set of neatly mounted plant specimens; the pages often contain extensive botanical information, setting them apart from typical herbarium specimens. In 1885, Wittrock began sending the volumes to C.G. Pringle, in exchange for receiving unique plant specimens to include in his Exsiccatae publication. Not only are the arrangements beautiful, but some sheets are even type specimens.