NOTES ON THE GENUS YUCCA. 285 
straight parallel tubes are found to fill the cells and to find their way, one to almost each ovule, I 
have followed them through both openings of the ovule, and found them attached with their 
enlarged end to the outside of the nucleus, separated from the germinal vesicle by two layers [30] 
of cells. It is probable that the minute, almost filiform, egg of the moth is carried with and 
between these bundles of pollen tubes as they elongate and push on into the ovarian cells and among 
the ovules. 
As soon as fertilized the nascent fruit of the capsular Yuccas (and apparently also of Clisto- 
yucca) becomes erect and its pedicel thickens and hardens, while the young fruit of Sarcoyucca 
remains pendulous, as the flower was, and as afterwards the mature fruit is, and its pedicel more 
flexible. . 
The Yuccas bloom from the early summer months to the end of the autumnal season. The 
first one in the latitude of St. Louis (all cultivated plants) is Y. angustifolia, which opens its flowers 
when the roses are in full bloom, from the middle to the end of May ; the true Y. jilamentosa makes 
its appearance next, about 10 or 14 days later; then come, one after another, different forms allied 
to the latter. Later than these, in July and August, Y. aloifolia unfolds its flowers, and Y. gloriosa 
very often, in our gardens as well as on the coast of South Carolina, blooms in September and even 
in October. 
FRUIT. 
The fruit of the Yucca is an oval or prismatic, more or less distinctly six-angled, more or less 
completely six-celled pod, usually with a short beak, bearing six rows of horizontal seeds. This pod 
is either pulpy and never opens, or it is dry and dehiscent, or it is intermediate between these 
extremes. Some of these conditions of the fruit were known to the older botanists ; Linnzeus (Syst. 
Nat. ed. X., 1759, n. 388) has a capsula trivalvis ; Gaertner (Fruct. II. p. 34, t. 85; 1791) figures 
and describes the fruit of “ Y. Draconis,’ as bacca carnosa ... . non secedens ; Nuttall (Gen. L, p. 
218; 1818), says: capsule opening at the summit ; but he mentions that of Y. gloriosa as pulpy ; 
Endlicher (Gen. n. 1117; 1836) tries to reconcile the apparent discrepancies by describing the cap- 
sule as subbaccata, demum achiscens; Kunth, Enum., and later botanists have followed Endlicher. 
In the Botanical Notes to Wislizenus’ Memoir of a Tour to New Mexico, etc., 1848, p. 101, I first 
distinguished the Yuccas with “juiceless capsules and thin seeds” from those with “succulent fruit 
and thick seeds.” Subsequent American botanists (Torrey in Bot. Mex. Bound. p. 221, and 
especially Chapman in Southern Flora, p. 485), confirm and adopt these differences. In [31] 
S. Watsou’s Botany of the 40th Parallel (Utah and Nevada), 1871, I have briefly characterized 
the four sections of Yucca, as I now understand them. 
The fruit in some Yuceas is pendulous, pulpy, and indehiscent, with a sort of crown or disc at 
base, consisting of the enlarged remnants of the perigonial segments and the stamens (Surcoyucca) ; 
in another, thus far only imperfectly known species, the originally fleshy fruit eventually dries up, 
and constitutes a spongy pericarp, which never opens, and is apparently erect, with a disc at base 
like the former (Clistoyucca) ; in a third group, the erect fruit is dry and capsular, the base is con- 
tracted into a short obconical stipe; it opens with three valves corresponding with the carpels and 
dividing the primary dissepiments, the valves finally divide again at tip (Chenoyucca); in the fourth 
group, represented like the second by a single species, the pod is similar to that of the last section, 
but opens at tip through the middle of the carpels loculicidally, the three valves remaining entire 
(Hesperoyucea). 
The secondary dissepiments are usually incomplete at base and top, and, at least in one form 
(Y. filamentosa), they are often rudimentary throughout; in Hesperoyucca they seem to tear 
irregularly at the dehiscence of the capsules. 
All the Yucea fruits, but more especially the capsular ones, and those of some species more 
