LILIACER, SILVA OF NORTH AMERICA. 3 
obscurely six-sided, nectariferous,’ glabrous, dull greenish white, three-celled, the cells divided by the 
development from the back of the carpels of secondary dissepiments, obtuse, or gradually narrowed 
into a short or elongated three-lobed style, the lobes emarginate and bilobed at the apex, ivory-white, 
and clothed with short epidermal hairs, and forming a broad triangular stigmatic tube, or slender and 
elongated, and crowned with a capitate three-lobed hyaline-papillate stigma penetrated by a narrow 
stigmatic tube (Hesperoyucca); ovules in six series, numerous, compressed, horizontal, short-stalked, 
anatropous. Fruit oblong or oval, more or less distinctly six-angled, six-celled, pendulous or erect, 
usually more or less beaked at the apex, surrounded at the base by the remnants of the perigone, 
baccate and indehiscent, or capsular, three-valved and dehiscent, dividing as it opens through the 
primary dissepiments, the valves finally splitting at the apex, or through the carpels loculicidally 
(Hesperoyucca) ; pericarp of two coats, the outer at maturity thick, succulent, and juicy (Sarcoyucca), 
or thin, dry, and leathery, and usually easily separable from the firm membranaceous or rarely 
succulent inner coat (Clistoyucca), or thin and woody, and adherent to the rather thinner 
membranaceous endocarp (Chenoyucca and Hesperoyucca). Seeds compressed, triangular, obovate 
or obliquely ovate or orbicular, thick with a narrow two-edged rim, or thin with a wide or narrow 
brittle margin; testa thin, more or less opaque, black, slightly rugose or smooth.” Embryo straight 
or more or less curved, diagonal, in plain or rarely ruminate hard farinaceous and oily albumen;°* 
cotyledon much longer than the short radicle turned toward the small oblong white hilum.* 
1 Septal nectar glands occur within the partitions which separate 
the cells of the ovary of Yucca, forming thin pockets extending 
from its summit nearly to the base, open at the apex, and, pouring 
their scanty secretions down through a capillary tube, discharge 
them through pores at the bottom of the ovary and opposite the 
inner segments of the perigone. (See Trelease, Bull. Torrey Bot. 
Club, xiii. 135, f. See, also, Brongniart, Ann. Sci. Nat. sér. 4, ii. 9 
[Mém. sur les Glandes Nectariferes de I’ Ovaire].) 
2 The three types of the fruit of Yucca correspond with three 
distinct methods by which the seeds are disseminated. In the first 
group (Sarcoyucca) the ripe fruit is thick, sweet, and pulpy, and is 
easily separated from the hard firm and core-like endocarp which 
closely invests the seeds. The fruits of this group, protected like 
those of all the arborescent species from the attacks of climbing 
animals by the decumbent sharp-pointed lower leaves, fall as soon 
as ripe, with the exception of those of Yucca aloifolia, while the 
succulent flesh is tempting to small animals and to birds, who, in 
In Yucca aloifolia the 
endocarp becomes succulent at maturity, and the fruit does not fall 
carrying it away, disseminate the seeds. 
when ripe, but dries up on the panicle when it is not eaten by birds, 
especially by the mocking-bird, who in feeding upon the pulp swal- 
lows many of the seeds, which it voids without affecting their vital- 
ity, and appears to be one of the principal agents for the dissemi- 
nation of the seeds of this species. (See Webber, Rep. Missouri Bot. 
Gard. vi. 96.) 
The distribution of the seeds of Yucca aloifolia is also assisted by 
the larve of the Bogus Yucca Moth (Prodoxus decipiens, Riley). 
The eges of this moth are deposited in the stalk of the young 
flower panicle, in which the larve burrow, and by their activity 
when preparing to hibernate late in the autumn when the fruits 
are dried up often cut it through, and, causing the panicle to fall 
to the ground, insure the spreading of the seeds. (See Webber, 
1. c. 103.) 
In the second group (Clistoyucca) the thick exocarp of Yucca 
arborescens becomes thin, dry, and spongy at maturity, and the 
lightness and roundness of the fruits which fall easily enable the 
wind to blow them about over the desert, thus breaking the peri- 
carp and scattering the seeds. 
In the fruit of the capsular species (Chenoyucca and Hespero- 
yucca) the pericarp becomes woody at maturity, splits through the 
centre and at the apex through the backs of the carpels, or opens 
loculicidally, allowing the thin seeds to escape from the erect cap- 
sules sometimes raised high in the air. (See Trelease, Rep. Mis- 
sourt Bot. Gard. iv. 223.) 
3 In germinating, the cotyledon remains partly under ground 
and within the seed, and does not grow into a leaf organ, the first 
leaf issuing from a split in the cotyledon opposite the remnants of 
the seed, and the leaves of the first season being in $ order. From 
the nodes of the first axis stout rootlets break through the back of 
the leaves, the earliest coming from the back of the cotyledon 
opposite the first leaf, and the radicle withers, or, in Hesperoyucca, 
the axis with the bases of the leaves swells out into a thickened 
bulb-like mass (Engelmann, Trans. St. Louis Acad. iii. 20). 
* By Engelmann (i. c. 34) the species of Yucca are grouped in 
the following sections : — 
Evyvucca. Filaments obtuse, papillose, free, or nearly so, from 
the segments of the perigone, spreading or recurved at maturity ; 
anthers cordate-sagittate ; pollen powdery ; style stout, papillose, 
rarely expanded at the apex. 
A. Sarcoyrucca. Panicle usually sessile. Fruit baccate, pen- 
dulous; exocarp thick and succulent; seeds thick; albumen 
ruminate. Stems generally arborescent. 
B. Cuiistoyucca. Panicle sessile or pedunculate. Fruit bac- 
cate, indehiscent, spreading or erect ; exocarp becoming dry and 
spongy at maturity ; seeds thick ; albumen entire. Stems arbo- 
rescent. 
C. Coznorucca. Panicles long-stalked. Fruit capsular, erect, 
septicidally dehiscent, ultimately splitting through the valves at 
the apex ; seeds thin ; albumen entire. Stems short or arbores- 
cent. 
Hesperorucca. Panicle long-stalked; filaments acute, gla- 
brous, erect at maturity ; anthers didymous, transverse, hirsute ; 
style slender ; stigma three-lobed, papillose. Fruit capsular, erect, 
three-valved, the valves entire; seeds thin; albumen straight. 
Stems subterranean. 
