336 



G. i?. Wieland — Notes on Living Cycads. 



But that these trunks do not differ greatly from other forms 

 is shown in figure 3. The scaly material below the crown of 

 leaves, and, lower down, the horizontal ridges just mentioned, 

 are the remnants of a true ramentum which is constantly dis- 

 appearing below as the age and size of the trunk increase. 

 And when this ramental material is lightly scraped off above, 

 preferably from a vigorous young trunk, the somewhat carrot 

 or turnip-like appearance is lost, and the spiral order of the 

 remnants of the leaf bases of former years is clearly to be seen. 

 The trunks of the Floridean cycads are hence, notwithstanding 

 their subterranean habit and unusual appearance, typical in 

 every respect. The slow elimination of the old leaf bases is 

 doubtless due in their case to growth in a protected underground 

 position, and may hence be a trunk habit secondarily acquired. 

 The subordinate position of these, comparatively speaking, 

 dwarf plants, as underbrush in large forests of pines, and in 

 the denser "hammocks" in the case of Z. pumila, has, together 

 with differential climatic change, probably, therefore, resulted 

 in the course of time in some diminution in size, an under- 

 ground habit, and nearly complete removal of the armor. 



4 Unquestionably the most inter- 



esting single point observed in the 

 cycads sent by Mr. Dickinson was 

 the presence on one of the cones 

 of a pinnule of normal form and 

 structure which had evidently 

 grown out from beneath the outer 

 hexagonal tip of one of the upper 

 abortive sporophylls. Figure 4 is 

 a faithful drawing of this monstrous 

 cone, so far as I know the second 

 thus far observed to bear leaf-like 

 growths in the Cycadese.* When 

 unpacked the pinnule it bore was 

 still somewhat green. As the par- 

 ent plant was in good condition 

 and at once planted, it was thought 

 that its examination could be some- 

 what deferred. But unfortunately 

 when the cone was examined a week 

 later, the pinnule, which was at 

 first strongly attached, had loosened, 

 so that its insertion was no longer 

 distinct. The thin sections I made 

 of the sporophyll to which it had 



* An anomalous $ sporophyll of Zamia Leiboldii Miq., bearing three 

 sporangia, has been figured by Mr. Worsdell, Vascular Structure of the Sporo- 

 phylls of the Cycadaceae, pi. xviii, fig. 25 (a), Ann. of Bot., vol. xii, No. xlvi, 

 June, 1898. 



Figure 4. — Zamia floridana 

 DC. x^. 



Miami, Florida, Nov. 15. 



Monstrous ovuliferous cone, 

 with sporophyll at (a) bearing 

 a pinnule of the normal struc- 

 ture and form seen in this 

 species. 



