Copies have resurfaced in the wake of the sale of Balkema to Taylor and Francis.
From the publisher's announcement:
This volume is the 14th in a series devoted to the flora of Ceylon. There are descriptions of most plant families, including: agavaceae; alismataceae; alliaceae; aloaceae; amaryllidaceae; anthericaceae; arecaceae; asparagaceae; berberidaceae; bromeliaceae; and cannaceae.