A REMARKABLE BUD 



SPORT OF PANDANUS" 



John H. Schaffner 



A SMALL specimen of Pandanus, 

 planted in a flower pot, had been 

 carrying on a precarious exist- 

 ance for many years in the bo- 

 tanical greenhouse of the Ohio State 

 Laiiversity, when in the fall of 1916 it 

 was transplanted into a bad of rich 

 earth in the aquatic room. This screw- 

 palm apparently belongs to the species 

 Pandanus iitilis Bory. The genera of 

 Pandanaceae — Freycinetia, Sararanga, 

 and Pandanus — are all described as 

 having spirally arranged leaves and ap- 

 parently all have three spirals. It is 

 not certain, however, from the descrip- 

 tions at hand, whether or not all the 

 species have the three spirals. 



The plant under consideration had 

 the normal three spirals of leaves char- 

 acteristic of the species and continued 

 this character for awhile after being 

 transplanted ; but the leaves imme- 

 diately began to grow larger and longer, 

 probably due entirely to the improved 

 soil and water conditions. Soon, how- 

 ever, the terminal growing bud under- 

 went a remarkable transformation and 

 sported in such an extreme manner that 

 the plant has ai^sumed an entirely new 

 aspect. The mutation resulted in a two- 

 ranked arrangement of the leaves in 

 which the spiral twist is entirely absent 

 (see Fig. 14). After growing for some 

 time, the plant took on the aspect of 

 a great fan. putting one in mind of a 

 traveler's tree, Raz'ciiala luadagas- 

 caricnsis. The last three leaves before 

 the change were each about 2 feet 1 

 inch long and quite rigid. The first two 

 leaves of the two-ranked portion were 

 also 2 feet 1 inch long and rigid, but in 

 the subsequent stages the leaves con- 

 tinued to become longer and very flex- 



1 Papers from the Department of Bota 

 376 



ible and recurved. The eighth and ninth 

 leaves were each 4 feet 3 inches long, 

 while the latest leaves produced meas- 

 ure 5 feet 3 inches in length. 



The families, Sparganiaceae and 

 Typhaceae, are closely related to the 

 Pandanaceae, and in passing up the 

 series to Typha one finds not only a 

 much more specialized type of flower 

 but also the more extreme conditions 

 represented in the herbaceous stem, 

 geophilous habit, two-ranked leaves, 

 and distinct internodes. The leaves of 

 Typha are still somewhat spiral in ar- 

 rangement, but have the prominent 

 sheath characteristic of many of the 

 highly evolved monocotyls. 



The Pandanales are probably more 

 closely related to the lower palms than 

 to any other group of plants, and the 

 palms approach such lower lily types 

 as Yucca and Cordyline. Among the 

 lilies and their relatives the change 

 from three to two spirals or to the 

 two-ranked condition is frequent, and 

 takes place even at the lower levels of 

 the evolutionary series. 



The palms are well known as mostly 

 trees with unbranched trunks and three 

 spirals of specialized leaves. Assuming 

 such an origin for the Pandanales, the 

 phyletic arrangement of the three re- 

 lated genera is as follows : Pandanus, 

 Sparganium, Typha. We have, then, 

 the following progressive series : 



1. From tree to geophilous. rhizome 

 herb. 



2. From three spiral leaves to two- 

 ranked condition with the spiral more 

 or less obliterated. 



3. From no internodes to well-de- 

 veloped internodes. 



4. From fleshy drupes to minute, 

 dry, nut-like fruits. 



ny, the Ohio State University, No. 113. 



