Located next to the Desert, it was built in 2011 to permanently house some great examples of succulent, which are the real “patriarchs” of the collection that could no longer be housed in greenhouses for winter shelter due to its dimensions. Funds necessary for the construction of the greenhouse were collected by a subscription campaign promoted by Prof. Anna Scoppola, the director of the Botanical Garden at the time.

In the greenhouse are cultivated arborescent specimens of Euphorbia L., including E. candelabrum Trémaux ex Kotschy, of Pachycereus (A.Berger) Britton & Rose, as P. pecten-aborigenum Britton & Rose and P. pringlei Britton & Rose, of Kalanchoe beharensis Drake, and representatives of Echinocactus grusonii Hildm., Myrtillocactus geometrizans f. cristatus P.V.Heath, Agave attenuata Salm-Dyck and Aloe dichotoma Masson. Two fine specimens of A. dichotoma Masson. were taken in Namibia by Prof. Angelo Rambelli, founder and first director of the Botanical Gardens.

A rich collection of succulent plants (“cactus”) is present and is divided into several sections according to the type of management and placement: The Patriarchs’ Greenhouse, the Astolfi Greenhouse with specimens grown steadily in the greenhouse, the Desert, and the Rocky ridge.