PULMONARIA (BORAGINEAE). Pulmonaria officinalis. Hildebrand has published a full account of this heterostyled plant. (3/11. ‘Botanische Zeitung’ 1865 January 13 page 13.) The pistil of the long-styled form is twice as long as that of the short-styled; and the stamens differ in a corresponding, though converse, manner. There is no marked difference in the shape or state of surface of the stigma in the two forms. The pollen-grains of the short-styled form are to those of the long-styled as 9 to 7, or as 100 to 78, in length, and as 7 to 6 in breadth. They do not differ in the appearance of their contents. The corolla of the one form differs in shape from that of the other in nearly the same manner as in Primula; but besides this difference the flowers of the short-styled are generally the larger of the two. Hildebrand collected on the Siebengebirge, ten wild long-styled and ten short-styled plants. The former bore 289 flowers, of which 186 (i.e. 64 per cent) had set fruit, yielding 1.88 seed per fruit. The ten short-styled plants bore 373 flowers, of which 262 (i.e. 70 per cent) had set fruit, yielding 1.86 seed per fruit. So that the short-styled plants produced many more flowers, and these set a rather larger proportion of fruit, but the fruits themselves yielded a slightly lower average number of seeds than did the long-styled plants. The results of Hildebrand’s experiments on the fertility of the two forms are given in Table 3.19. TABLE 3.19. Pulmonaria officinalis (from Hildebrand). Column 1: Nature of the Union. Column 2: Number of Flowers fertilised. Column 3: Number of Fruits produced. Column 4: Average Number of Seeds per Fruit. Long-styled by pollen of short-styled. Legitimate union : 14 : 10 : 1.30. Long-styled 14 by own-pollen, and 16 by pollen of other plant of same form. Illegitimate union : 30 : 0 : 0. Short-styled by pollen of long-styled. Legitimate union: 16 : 14 : 1.57. Short-styled 11 by own-pollen, 14 by pollen of other plant of same form. Illegitimate union : 25 : 0 : 0.