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SCIENCE 



[N. S. Vol. XL. No. ia25 



our cultures, is without rays. Both variations 

 are fairly common among the Compositse, and 

 the characters may become specific, as in the 

 rayless species Gaillardia suavis; or even 

 generic, as in Hymenopappus, which has no 

 rays.2 Messrs. Sutton & Sons, of Eeading, 

 England, inform me that they introduced the 

 primrose-rayed variety of the common sun- 

 flower in 1889 ; it had occurred as a sport from 

 the ordinary form a few seasons before. We 

 have shown by breeding that it is recessive to 

 the orange-rayed (normal) form, and segre- 

 gates in a normal Mendelian manner. On 

 August 19, 1913, my wife and I found near 

 Goodview, Colorado, a lot of wild sunflowers 

 (H. annuus subsp. lenticularis) growing in 

 very dry ground by the roadside, and conse- 

 quently very small. In the midst of the nor- 

 mally colored plants was a single example of a 

 primrose-rayed variety,^ which I dug up with 

 great difficulty, owing to the very hard dry 

 soil, and removed to the garden, to be used in 

 crosses. Here, in this poor little starved plant, 



2 Leucampyx newierryi Gray and Hymenopap- 

 pus radiatus Eose are rayed Bymenopappus, 

 though the Leucampyx retains the primitive char- 

 acter of disc-bracts, while otherwise almost iden- 

 tical with H. radiatus. Nelson states that Leu- 

 campyx has no pappus, but this is an error; it has 

 pappus-scales like those of Symenopappus. 



3 Helianthus lenticularis var. primulinus, nov. 

 Bays primrose color; disc-corollas very pale yel- 

 lowish-green or greenish-yellow, the lobes faintly 

 tipped with reddish; disc-braets dark at end; stig- 

 matic branches pink, dark at end, the general ef- 

 fect to the naked eye pale lavender. Leaves very 

 broad, thick, hoary. In the garden variety {an- 

 mms var. primulinus), the plant compared being 

 one extracted in the Fj from primulinus X coro- 

 natus, we find the stigmatic branches almost black, 

 while the lobes of the disc-corollas have the apical 

 part, and the margins below that, dark lake; even 

 the pappus scales are deep lake. Hence the gen- 

 eral effect of the disc is very black, very different 

 from the normal form. We have obtained, how- 

 ever, another garden variety (S. annuus var. selene, 

 nov.) with the disc pale greenish yellow; rays light 

 primrose; stigmatic branches pale primrose. The 

 plant is about 5 feet high; stem without purple; 

 leaves large; involucral bracts long-pointed, lateral 

 cilia short and not conspicuous. 



we had what might have been the origin of a 

 whole series of primrose-rayed varieties, greatly 

 adding to the beauty and interest of gardens, 

 had not Sutton obtained an analogous form 

 years before. As it is, we hoped to see some 

 interesting modifications through the introduc- 

 tion of the wild strain into the cultivated 

 group. 



On the same day that we found the wUd 

 primulinus, we also found a form* of H. aridus 

 Eydberg with lemon-yellow rays, a shade inter- 

 mediate between orange and primrose. This 

 H. aridus is treated by Nelson as a synonym 

 of H. petiolaris, but this is certainly an error. 

 Its characters strongly suggest that it is a 

 lenticularis X petiolaris hybrid. It is not 

 merely lenticularis growing in dry ground, for 

 that plant in the driest places does not become 

 aridus. 



In the cases just cited, we seem to be con- 

 cerned with the dropping out of a determiner, 

 but we have other examples which will not bear 

 this interpretation. Repeated experience in 

 breeding has shown that the coronatus char- 

 acter (red on the rays) is a typical Mendelian 

 dominant, but its expression is very variable. 

 We noted in the case of the original plant, 

 that the last small heads of the season were 

 almost entirely yellow rayed. We have also 

 observed that heterozygous plants may have 

 very richly colored rays. Mr. Tufnail, of the 



* Heliantlius aridus var. citrinus, nov. Kays 

 lemon yellow. It does not follow, because there are 

 at least three degrees of yellowness (corresponding 

 approximately to Bidgway's cadmium yellow, 

 lemon chrome and picric yellow) in sunflower rays, 

 that there are three kinds of pigment. Bays of 

 H. annuus var. primulinus, which are picric yellow, 

 on drying for the herbarium turn brilliant light 

 lemon yellow. Examining rays of garden sunflow- 

 ers under the microscope, it is seen that in the 

 normal (cadmium yellow) and lemon (lemon 

 chrome) forms the pigment nearly fills the cells, 

 and is differently colored in the two. In the prim- 

 rose variety, however, the pigment is much less 

 abundant, as well as paler. It is perhaps prob- 

 able that the pigment of the primrose variety is 

 quite the same as that of the lemon one, appearing 

 paler only because not massed; there are then two 

 types with regard to its density or abundance, the 

 combinations of these producing three varieties. 



