In this paper we present the Clover architectural model, a new conceptual architectural model for groupware. Our model results from the combination of the layer approach of Dewan's generic architecture with the functional decomposition of the Clover design model. The Clover design model defines three classes of services that a groupware application may support, namely, production, communication and coordination services. The three classes of services can be found in each functional layer of our model. Our model is illustrated with a working system, the CoVitesse system, its software being organized according to our Clover architectural model. Keywords Conceptual Software Architecture, Clover Design Model.