The soft, bright green to pale green leaves of Aspalathus spinosa subsp. flavispina are trifoliolate, the leaflets slightly flat-bladed to thread-like or cylindrical and blunt-tipped. The often-straight leaflets vary in length, the secondary leaves growing at many nodes always shorter.
The sharp, straight spines among the leaves are yellow to cream. The subspecific name, flavispina, is derived from the Latin words flavus meaning yellow and spina meaning thorn, referring to these fierce though yellow appendages that defend, contributing to plant wellbeing and even longevity (Vlok and Schutte-Vlok, 2015; JSTOR; iNaturalist).