Stout: Sterility in Lilies 



371 



SEED OF THE SEEDLESS TIGER LILY 



Figure 18. While the Tiger Lily has thus far failed to yield pods to intra-specific pol- 

 lination, many have been obtained to pollen of L. maximowiczii, as is proved by the two 

 fine pods on the plant at the right. To the pollen of L. zvarleyensc only imperfect pods 

 were developed, as shown in the two upturned but partly developed pods on the left. 

 The Tiger Lily is evidently able to produce seed and its usual sterility is due to physiological 

 incompatibility of the pollen used, and is not in any way connected with the fact that 

 the plant habitually reproduces by means of bulbs. 



In an effort to discover compatible 

 fertilizations that would produce seed 

 on the Tiger Lily, bulbs of this species 

 have been secured from widely sepa- 

 rated localities, some even coming di- 

 rectly from apparently wild plants in 

 China. All plants grown from these 

 have, so far as tested, failed to yield 

 fruits either by self-pollination or by 

 cross-pollination between the different 

 strains. Capsules also failed to form 

 when pollen of such species as L. can- 

 adcnsc, L. supurbum, L. hcnryi, L. 

 speciosum, L. auratum, and L. hiim- 

 boldtii was used. To pollen of L. zvar- 

 leyensc, the ovaries of the Tiger Lily 

 began to enlarge and become upturned 

 (see Fig. 18), but the capsules did not 

 develop fully and yielded no seeds. 

 But when pollen of L. maximowiczii 

 was used fine pods were readily ob- 

 tained (see Fig. 18). Potted plants. 



plants grown in the open, old plants 

 of vigorous vegetative growth, and 

 plants from bulblets blooming for the 

 first time have all produced fine pods 

 from the flowers thus pollinated. Yet 

 on these same plants complete failure 

 resulted from all attempts to produce 

 seed by self-pollination. 



It is clear that these usually sterile 

 plants are able to form fruit and seeds 

 and that their pollen is potent, provided 

 there are compatible relations in fer- 

 tilization. The bulb and the bulblet- 

 forming habits of growth, and of veg- 

 etative propagation do not render seed 

 production impossible. The sterility is 

 that of physiological incompatibility in 

 fertilization, a well-marked type which 

 is also seen in numerous species that 

 naturally reproduce exclusively by 

 seeds, and is by no means peculiar to 

 plants that reproduce vegetatively. 



