1. Monographie der Gattung Koeleria. By Dr. Karl Domin. With 22 plates and 3 maps. 4to. Stuttgart, 1907.

This elaborate monograph occupies four complete parts of Luersen's “Bibliotheca Botanica,” and covers more than 350 quarto pages. It is divided into three main parts, the first dealing with the history and morphology of the genus; the second, which occupies by far the greater portion of the work, being devoted to the systematic arrangement of the species and their varieties; while the third is concerned with the facts of geographical distribution and the probable phylogeny of the species. The systematic portion is drawn up on most liberal lines. Previous writers have treated Koeleria as a small genus containing considerably less than a score of species. Hooker and Bentham, in the “Genera Plantarum,” accepted twelve species, and Hackel, in “Die Naturlichen Pflanzenfamilien,” only increased the number to fifteen. But Dr. Domin describes no less than sixty-one, and even then he is careful to state that several of these are “collective species,” and that the full number is eighty-nine. Many of his “species” are further separated into subspecies, varieties, subvarieties, forms, &c. As an instance of the laboriously minute treatment adopted, it may be mentioned that the variable K. gracilis (the K. cristata of most authors) is divided by Domin into fourteen subspecies. The first of these is again separated into twelve groups, which are further split up into forty-four varieties. Altogether, Domin describes rather more than 170 forms of Koeleria gracilis, his account of that species alone occupying sixty-five pages of his monograph! It may be asked to what extent a monograph of the New Zealand species of Veronica would stretch if prepared on similar lines.

New Zealand botanists have been accustomed to include all our Koelerias within the compass of a single species, which for many years was considered to be a form of K. criatata. When preparing the Manual I followed Hackel's views in referring our plant to a South American species distinguished by him as K. Kurtzii (equivalent to K. Bergii Hierony, according to Domin); but Dr. Domin considers that we have three endemic species in New Zealand. These he places with six South American, two Australian, and two Asiatic species in a group to which he gives the name of Dorsoaristatae. The following key to the New Zealand species is adapted from his work:—

The first of these species is based upon specimens collected by Dr. Cockayne in the Otira Gorge; K. superba was gathered by myself on the mountains above the Broken River, Canterbury; and K. Gintlii in the Hooker Valley, Mount Cook district.

Although it is impossible not to feel that the multiplication of species has been carried to an inordinate degree, there are many points of excellence in Domin's memoir; and it can fairly be said that it contains much original work of a high order, and that he has treated his subject in a most complete and exhaustive manner.

T. F. C.