Introduction

The Section Acutae Fries of the genus Carex L. has presented considerable difficulty to New Zealand botanists owing to the apparent polymorphy of its members. In 1884 Cheeseman made an attempt to sort out the confusion, a treatment which Kukenthal, in his monograph of the genus, largely maintained, although he made several changes in rank of Cheeseman's taxa. The only source of information for most New Zealand botanists has been the Second Edition of Cheeseman's Manual which follows the 1884 treatment.

The group is therefore long overdue for revision and the present paper is a preliminary attempt to clarify the position with regard to the names already published. Sufficient information has not yet been gathered, either as specimens in herbaria or in the form of field notes, to enable a more comprehensive revision to be made at this date. A far more searching study of all the forms occurring will be necessary before the group can be considered satisfactory both from taxonomic and ecological points of view.

The main difficulty has been the lack of recognition of useful characters for delimitation of the various taxa. Examination of available material reveals certain bases for determination which have been set out in the key to the species and further outlined in the descriptions.

The variability of the species, as previously understood, makes the recognition of taxa extremely difficult, and without a considerable range and number of specimens an analysis is almost impossible, but it is found that on the basis of the characters here employed the specimens sort out into very distinct groups with remarkable uniformity, the difficulties being largely confined to C. ternaria Forst. f. ex Boott, defined below as C. geminata Schkuhr. Although the majority of the specimens clearly refer to this species there are a number of specimens possessing a wide range of minor characters whose taxonomic positions are not yet certain. No attempt is made to describe these latter as a hasty publication probably requiring later emendation would, far from clarifying the position, only lead to further taxonomic and nomenclatural confusion.

Name changes have been made where required by the International Rules, 1936.