Further Studies on the Apogamy and Hybridization n{ the Hieracia. 247 



Table I, where they have been put down alphabetically. The species 

 belong to both sections : Aurella and Accipitrina into which A. Peter 

 (1894) in Engler & Prantl, Natürliche Pflanzenfamilien, divides 

 Archicracium, and almost all the 23 groups, into which the two 

 sections have been divided, are represented. Of course, it would be 

 desirable to get more of the aberrant species examined than I have 

 succeeded in getting into cultivation, but the seed catalogues do not 

 present many more than I have got hold of, and otherwise it is difficult 

 to get seeds. I may especially point out the desirability of studying 

 the South European forms (mostly group Italica Peter) and the 

 group PseudostenotJieca where differences might perhaps be found. 



Of the species enumerated in the table, I may direct attention to 

 H. alpimmi L., var. Halleri YiW.; it has the pecuUarity that the heads 

 never open; the yellow tips of the corollas are seen peeping out of 

 the bracts, but they do not reach farther. In spite of this, the plant 

 has plenty of fruits with seeds capable of germinating. On the whole 

 several forms of H. alpimmi seem to have this peculiarity, in good 

 harmony with the apogamy. 



Further it is worth noticing that H. canadmse Michx. which is 

 classed among the group Umbellata, is apogamic, in contrast to its 

 allies, H. mnbellatum and H. lactaris. Furthermore, it is a native of 

 North America, so that not all North American species require ferti- 

 lization, as do the species of Stenotheca. — With regard to our northern 

 Archieracia I think I can say that I have examined species of all groups 

 and found that all are apogamic with exception of H. mnbellatuin. 



If we turn to the question, if something can be said numerically 

 whether the species are absolutely apogamic or not, I think that 

 the numbers given in Table I permit the following conclusion: by 

 far most of the examined species are absolutely apogamic. 

 The percentage of full fruits is not disturbed by the castration in 

 any degree worth mentioning, and the deviations go now to the 

 one, now to the other side. 



The numbers given under H. pulmonarioides Vill. present a fine 

 example. Of this easily recognisable species I have had experiment 

 plants from 4 different sources, and they formed fruits very well and 

 did not show any dissimilarity in their outer appearance. Of these 4 

 sets one shows a slight tendency in favour of the castration 

 (83:80 p. ct.); while the others go a little to the other side (97:99; 

 97:98; 69:76 p. ct.); these numbers refer to a great many fruits 

 and are therefore more trustworthy than many of the other numbers. 



