180 PHYSIOGNOMY OP PLANTS. 



appearance produced by the square shape of their stems, by 

 flattenings not caused by any external pressure, and by 

 riband-like wavings to and fro. Cross sections of Bignonias 

 and Banisterias shew cruciform or mosaic figures produced 

 by the mutual pressure and interpenetration of the stems 

 which twine around each other. (See very accurate draw- 

 ings in Adrien de Jussieu's Cours de Botanique, p. 77-79, 

 fig. 105-108.) 



(26) p. 27." The form of Aloes." 

 To this group of plants, characterised by so great a simi- 

 larity of physiognomy, belong ; Yucca aloifolia, which extends 

 as far north as Florida and South Carolina ; Y. angustifolia 

 (Nutt. ) which advances as far as the banks of the Missouri ; 

 Aletris arborea ; the Dragon-tree of the Canaries and two 

 other Drsecaenas from .New Zealand ; arborescent Euphor- 

 bias; Aloe dichotoma (Linn.) (formerly the genus Bhipi- 

 dodendrum of Willdenow) ; and the celebrated Koker-boom 

 of Southern Africa with a trunk twenty-one feet high and 

 above four feet thick, and a top of 400 (426 Engl.) feet in 

 circumference. (Patterson, Eeisen in das Land der Hotten- 

 totten und der Kaffern, 1790, S. 55.) The forms which 

 I have thus brought together belong to very different 

 families : to the Liliacese, Asphodelese, Pandanese, Ama- 

 ryllidese, and Euphorbiacese ; all, however, with the 

 exception of the last, belonging to the great division 

 of the Monocotyledones. A Pandanea, Phytelephas ma- 

 crocarpa (Ruiz,) which we found in New Granada on 

 the banks of the Magdalena, with its pinnated leaves. 



