AGAVE IN THE WEST INDIES—TRELEASE. 13 
detachable border in species like A. lophantha, or the fibrous shredding away of the margin 
in such species as A. filifera; and a considerable number of euagaves, such as A. atrovirens, are 
marked by a partial hardening of the edge, so that the prickles are connected by it, at least 
near the end of the leaf. The Antillean groups do not present any of these characters, but a 
large part of the species described in the present paper have the leaf margin of such a texture 
that in maturity it.dries into a parchment-like border, either for a short distance below the 
end spine or throughout. In some species, especially of the Caribaeae, this border is conspicu- 
ously red during the early life of the leaf, and the original leaf description of A. Karatto has 
been misunderstood because it included mention of such a marginal coloration. 
INFLORESCENCE.,! 
Apart from the very obvious difference between the spicate inflorescence of Littaea and 
the paniculate inflorescence of Euagave, obscured in such representatives of the former subgenus 
as Agave utahensis? and A. Engelmanni, the relative elongation of the scape below the flower 
cluster shown when the long-stalked panicle of A. Cocui (pl. 6) is compared with the nearly 
sessile panicle of A. Legrelliana (pl. 60) or A. Underwoodia (pl. 68) is generally, if not constantly, 
characteristic. This is also true, with reasonable limitation, of (a) the crowding or separation 
of the scape bracts, dependent on the greater or less lengthening of internodes; (b) their 
breadth of form (A. Trankeera, pl. 25, and A. Eggersiana, pl. 31), a feature which is not always 
the result of difference in diameter in the scape and attendant width of their bases; and (c) 
their erect or spreading direction. Subject also to limitation, but diagnostic, are the differences 
in the length of the panicle branches and the consequent shape of the inflorescence shown by 
A. Underwoodii (pl. 68) and A. missionum (pl. 74). The most characteristic differences in the 
inflorescence, however, lie in the greater or less branching and extension of the panicle branches, 
which is evident when such forms as A. Willdingu or A. Nashii (pls. 93 and 101) and A. Legrel- 
liana (pl. 60) are contrasted. The relative length of the pedicels in which these branches end 
either accentuates (A. Legrelliana, pls. 60 and 61) or diminishes (A. Willdingvi, pls. 93 and 94) 
the separation of the flowers, and can in general be depended on in the segregation of species. 
FLOWERS.‘ 
In the flowers themselves, which are much frequented by insects and birds of several 
groups, differences in color and odor are often very marked, as when the greenish fetid flowers 
of Agave sisalana are compared with the yellow pumpkin-scented flowers of A. Eggersiana or 
the orange-throated flowers of A. Legrelliana or A. antillarum. Unfortunately such characters 
as odor are not preserved in herbarium specimens, and the color of the flowers may be lost in 
drying them. Generally, size, shape, and proportion of the flowers of a plant are counted on 
as being fairly constant. Perhaps this is as true in Agave as in most genera, and such differ- 
ences sufficiently distinguish the small, short-stamened flowers of A. Willdingii (pl. 94), the 
rather large, long-stamened flowers of A. fourcroydes (pl. 112) with urceolately contracted tube, 
and the very large conical-tubed flowers of A. Legrelliana (pl. 61). Neither size nor proportion 
is satisfactorily limited, however, and in flowers with an inferior ovary, such as these, the form 
and measurements of the germen and its proportion to other parts of the flower have to be 
accepted with caution, as possibly influenced by the age of the flower or the time that has 
elapsed since fertilization was effected. Measurements of the flower are further dependent 
very largely on its freshness or the manner in which it has been preserved, and though well- 
pressed flowers may give measurements closely comparable with those of fresh flowers, informa- 
tion of this kind derived from withered flowers like those shown on plate 40 is of only very 
general value. 
One of the most useful floral characters in Agave is afforded by the height at which the 
filaments are inserted in its perianth tube. Engelmann, who first applied this character com- 
1 Engelmann, Trans. Acad. Sei. St. Louis, vol. 3, 1875, p. 295; Bot. Works, 1887, p. 302. 
2 Pop. Sci. Mo., vol. 28, 1886, p. 11, fig. 9. 
3 Rept. Missouri Bot. Gard., vol. 3, 1892, pl. 55. 
4 Engelmann, Trans. Acad. Sci, 8t. Louis, vol. 3, 1875, p. 297; Bot. Works, 1887, p. 303. 
