TEANSAOTIONS 



ACADEMY OF SCIENCE OE ST. LOUIS. 



Notes on the Genus Yucca. 



By George Engelmann, M.D, 



The stately Yuccas of liliaceous alliance and of American origin 

 had attracted the attention of European horticulturists long before 

 Linnaeus classed the then known species, four in number, and, 

 indeed, three of these were based on specimens cultivated in Euro- 

 pean gardens, two of them, Tucca aloifolia and Tucca Draconis^ 

 on the elegant and very accurate figures of cultivated plants by 

 Dillenius, published some £40 years ago. Ever since then the 

 Yuccas have remained favorite plants in the gardens on account 

 of their palm-like (hence Palmilla of the Mexicans), either rigid 

 and pungent, or gracefully curved foliage, shooting up from the 

 ground in pleasingly regular masses, or raised into the air on sim- 

 ple or branching trunks, all overtopped by immense white pani- 

 cles of hundreds of glorious flower-bells. 



It thus happened that these plants fell into the hands of pro- 

 fessed horticulturists, and — perhaps because the herbaria could 

 afford only few and very incomplete specimens — scientific botan- 

 ists rather shunned them, as they did many other such plants, and 

 notably among them the Cacti. With these they share the pre- 

 cious property of being easily propagated from some, perhaps a 

 single, imported specimen ; hence, the individual peculiarities of 

 such specimens, propagated a thousand and a thousand fold in the 



iii — 2 * [April 15, 1873.1 



