896 THE JOURNAL OF BOTANY 
do well to place them on their shelves. But a Flora of the Hast 
Riding and a Flora of Liverpool, worthy to take their place beside 
those of Middlesex or of Plymouth, have yet to be written. 
Missouri Botanical Garden. Thirteenth Annual Report. By Wm. 
TreLEase, Director of the Garden. 8vo, pp. 133, with 106 
plates. Published by the Board of Trustees, St. Louis, Mo. 
the Director, Mr. Trelease. Mr. J. G. 
Aloinee and Yuccoidee” (Journ. Linn, Soe. xviii. (1880) p. 148), 
recognized a close association between the Old World Aloe and a 
few allied African genera, on the one hand, and the New World 
nera Yucca, Hesperaloe, Herreria, Beaucarnea, and Dasylirion, com- 
prising the Yuecoidee, on the other. The distinguishing features 
are the thick fleshy leaves and gamophylly of the Aloinee, and the 
less succulent, more fibrous leaves and free petals of the Yuccoidee. 
In the Genera Plantarum (1883), Bentham and Hooker, the groups 
are again closely associated, but the exclusively New World Yuccoidee 
becomes the larger tribe Dracenea by the inclusion of Dracena and 
allied Old World genera. The distinct petals supply the chief 
diagnostic character of the larger group. 
Prof. Engler, in the Pflanzenfamilien (ii, 5, 1888), has adopted 
a different arrangement, placing the 4loinee at some distance from 
Dracenoidee, which he subdivides into Yuccee, including Yucca, and 
the monotypic Texas genus Hesperaloe; Nolinea, also New World, 
with Nolina and Dasylirion; and Dracenea, a small group of Old 
World genera, The petals united at the base in Dracenea separate 
this group from the other two, which are distinguished inter se by 
the insertion of the anthers, and the number, arrangement, an 
colour of the seeds. Mr. Trelease deals only with the small group 
Yuecee, which is characterized by having similar subequal withering 
but persistent perianth-segments, a three-celled ovary with more or 
less intruded dorsal false septa, many ovules in two ranks in each 
cell, a subterete elongated embryo placed obliquely across the seed, 
and germination with arched cotyledon, the seed remaining in or on 
the soil, instead of being directly carried up on the end of the 
cotyledon, as commonly happens in Liliaceae. 
lve genera are recognized—Hesperaloe (2 species), Hesperoyucca 
(1 species), Clistoyucca (1 species), Yucca (28 species), and Samuela 
(2 species) ; the last named has been separated by the author from 
Yueca on account of having the perianth distinctly tubular and, 
gamophyllous below. Clistoyucca is the Yucea arborescens Torr., the 
Joshua tree of the Mohave Desert region, which Mr. Trelease has 
raised to generic rank, adopting the sectional name under whi¢ 
r. Engelmann had distinguished it from the other species of Yucca. 
é numerous and excellent plates, a large number of which 
are photographs from growing plants, are a valuable addition to 
the descriptive text. BR 
A. B. &B. 
