Two species of Calandrinia H. B. K. have been found in the Netherlands as aliens or escaped from cultivation: C. elegans Spach, from California and C. compressa Schrad. ex DC., from Chile. They can be distinguished as follows: 1. Leaves of the involucre (‘calyx’) free, ovate, acuminate at the apex, about half as long as the perianth (‘corolla’), in fruit 8—12 mm long. Capsule slightly shorter than to as long as the involucre ............................... 1. C. elegans 1’. Leaves of the involucre connate at the base, slightly shorter than the perianth, in fruit 5—7 mm long, the free portion broadly triangular and acute. Capsule longer than the involucre... ................................ 2. C. compressa