Having an uneven number of pinnae, by virtue of having one terminal pinna. ... Compare: paripinnate. ... (09 Oct 1997) ... Found on http://www.encyclo.co.uk/local/20973
Im·par'i·pin'nate adjective [ Latin impar unequal + English pinnate .] (Botany) Pinnate with a single terminal leaflet. Found on http://www.encyclo.co.uk/webster/I/16