Within Paullinieae, fruit are schizocarpic, separating into samaroid mericarps or septifragal capsules which expose the seeds.
Paullinia, Cardiospermum and Urvillea have septifragal capsules (ACEVEDO-RODRIGUEZ, 1993; BARROSO et al., 1999) and the last two mentioned are most closely related (FERRUCCI, 2006).
It is important to say that there is no impediment to the rupture of the thin endocarp in the inner portion of the septum, which could result in a septifragal opening as well.
ulmacea is a septicidal capsule and additionally septifragal, like in Cardiospermum.
In agreement with Weckerle and Rutishauser (2005), in Paullinieae, schizocarpic fruit or septifragal capsules are structurally similar and, as in the ovarian wall, the pericarp gives useful anatomical characters to the generic and infrageneric grouping in Sapindaceae.