11.—29.

of time involved in this work was well repaid by the knowledge that the competition resulted in a great deal of knowledge of our grasslands being gained by the youthful competitors. The Junior Red Cross is to be congratulated in the valuable work it is doing in interesting young New-Zealanders in the country's most important industry—grassland farming. A further competition is to be held and the Assistant Director-General and myself have prepared a pamphlet on grassland knowledge for the assistance of the entrants. A similar competition was instituted by the Friends' School, Wanganui, and was judged on similar lines. It; is pleasing to note this activity in real useful nature-study. (b) The Herbarium. —The herbarium is an indispensable adjunct both to routine and research work, and has been still further improved during the year. The New Zealand section (indigenous and introduced species) now contains over seven thousand five hundred specimens, while the section of foreign plants (selected with especial reference to their importance for research on the introduced flora) numbers well over four thousand specimens. This has been made possible by continuing the system of exchange of material with the leading herbaria abroad. The whole of the collection has now been mounted and properly arranged for case of reference. But the rapid expanse of the collection and the inadequate space available make conditions for working far from ideal. (c) Assistance and Advice to other Officers of the Station.—As in previous years, this work has been done as occasion required. I wish to acknowledge the assistance given to this section by the various officers. (d) Plot Work. —The area allotted to me on the Experimental Area has proved of great service for growing critical specimens to a stage fit for examination, and for the prosecution of various researches that we have in hand. It has proved of especial service for the investigations being carried out on grasses, piripiri, brassicas, and various weeds. Mr. Zotov has devoted a good deal of time to this work, with excellent results. 2. General Research Work. Under this head I refer to the two main activities of the section —the study of the grasses of New Zealand (both indigenous and introduced) and that of the alien flora. Both of these are of considerable magnitude, and obviously cannot be completed within a short space of time. This needs noting, as we have found in both groups that the existing state of knowledge was in a very unsatisfactory condition. Hardly any critical work had been done on the grasses, and numerous errors of identification have been found in the received lists of alien species. Nor had any satisfactory attempt been made to assess the real economic importance of many of the species concerned. It is proposed to publish the results of each research in bookform, while dealing with certain problems by way of special papers. It would also appear that there is a need for a smaller illustrated book dealing with the chief grasses and clovers and their identification. (a) Grasses.—The following large genera have been revised : Agrostis, Deyeuxia, Poa, Danthonia, Festuca. Work on the other groups, and on structure and economic ecology is well advanced. A number of keys for easy identification have been framed and tested out. A technical paper on Festuca is being sent for publication. Mr. Zotov has continued the preparation of illustrations. He has also made a special study of leaf-sections of all the grasses, made drawings of these, and is preparing a key based, on leaf-characters. This work has already proved of great value in our own investigations, and breaks new ground in New Zealand botany. (b) Alien Flora.—During the • year over twenty new species have been added to the list of naturalized plants, largely as a result of the work on identification of specimens sent in. In addition, a number of others have been found tending to establish themselves. Of the new records some are of plants occupying considerable areas, and evidently established years ago, though they have not before been brought into notice. Among the new records may be mentioned as decidedly undesirable incomers, Carthamus lanatus (saffron thistle), Calycotome spinosa (a spiny shrub from the Mediterranean), Eupatorium adenophorum (Mexico ; there are two other species established of this genus, which contains some poisonous plants), Oxylobium ellipticum (the genus is said to be one of the most poisonous in Australia), Hordeum jubatum (squirrel-tail; America). This last has recently been sent in from Central Ota go, where it would find conditions very suitable for its multiplication. Although rather ornamental, it is regarded as one of the most injurious weeds, causing severe ulceration in animals that eat it. These examples are given not in any alarmist spirit, but as evidence of the good work that can be done by sending in prompt notice of any plant not before observed in the weed flora. The names given in previous lists of alien species have proved in a number of cases erroneous. The necessity for having our alien flora correctly named hardly needs emphasizing, but I mention two cases as illustrations of its importance. When examining specimens hitherto called Helenium quadridentatum I found that the plant under consideration could not possibly be that species. It proved to be H. puberulum. The importance of a correct identification lay in the fact that several species of the "genus are poisonous to stock. Acclimatization societies have often endeavoured to have Canadian wild rice (Zizania aquatica) introduced, as it is one of the best of the duck-feeds. The plant had, however, an extremely bad reputation, as it was supposed to be naturalized on the Northern Wairoa River. The plant there growing certainly has several very objectionable characters, but it is the Manchurian species (Zizania latifolia). In view of these facts, I have made a critical study of all the alien species, and prepared a preliminary account of them. This is being thoroughly revised before being offered as a handbook. 3. Special Researches. (а) Rushes.—Mr. Zotov has completed a revision of the rushes and their hybrids occurring in New Zealand. This is a necessary preliminary to the study of their economic ecology. (б) Piripiri.—An investigation into the distribution and systematics of the grassland species of Acaena is under way, in connection with the insect-control work being carried out at the Cawthron Institute. The botanical side of the work is being greatly assisted by the enthusiastic co-operation of the field staff of the Department of Agriculture. (c) Brassicas.—A number of aberrant forms of Brassica have been sent in, and it seemed well to commence a detailed study. Work up to date suggests that hybridism is largely the explanation of these forms, especially in the swede-rape group. (d) Hybridism.—The researches on hybridism in the New Zealand flora are being continued as opportunity offers. A complete list of the hybrid groups so far discovered is under preparation, in collaboration with Dr. L. Cockayne, C.M.G., F.R.S. (e) General Systematics of the New Zealand Flora. —This is also being proceeded with as opportunity offers, with especial reference to the information gained during my period of work at the herbarium of the Royal Botanic Gardens, Kew, Several papers are now ready for publication.

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