NOTES ON THE GENUS YUCCA. 283 
The six STAMENS, in two series, but of nearly equal length, are adnate to the base of the perigone, 
and always shorter than this, and mostly shorter than the pistil; only in Hesperoyucca they are 
longer than the latter. Straight in the bud, they are frequently more or less recurved and even 
uncinate after maturity, in some forms more, in others less; but I am not able to discover a specific 
character in this change of form. 
he filaments are fleshy and club-shaped, and in the true Yuccas covered, especially upwards, 
with transparent one-celled papillae or papillose hair; a minute point on the obtuse, sometimes 
slightly trilobed apex bears the introrse anther. In Hesperoyucca the filament is smooth, thicker 
upwards, but with an acute tip. 
The anthers are comparatively small, 2} or usually 3-4 mm. long; in exceptional cases, only 
in cultivated plants of Y. angustifolia, I have seen them 5-6 mm. long; they are sagittate or cordate 
at the base, rounded and entire or notched at tip, adnate on the back and two-celled; they open 
longitudinally just before the perigone expands, and contracting to one-third or less of their size 
and curling backwards, expel the large, comparatively scarce, globose, glutinous pollen-grains of 
0.055-0.070 mm. diameter. The size and shape of the anthers seem to me to vary in the same 
species. 
Hesperoyucca has smaller, deeply cordate, emarginate, somewhat didymous anthers, 14-2 mm. 
long, and broader than long, bearing pollen similar to that of the other Yuccas. 
The PIsTIL in the true Yuccas is a cylindric or rather prismatic, obscurely six-sided ovary, [27] 
sometimes irregularly impressed and angled by the close application of the stamens in the 
bud, rarely attenuated at base ; terminated by three more or less united stigmas, which are usually 
sessile, or are elevated on a style formed by the gradually attenuated upper part of the ovary. Only 
in Y. Guatemalensis the ovary is more oblong than prismatic. 
The ovary consists of three carpels, opposed to the exterior perigonial lobes, forming by their 
connection three primary dissepiments, each one bearing on two central placente two series of num- 
erous flat, horizontal anatropous ovules on very short (not long, as is sometimes stated) funiculi, sep- 
arated from one another by a secondary dissepiment springing from the back of the carpel; the 
single ovules, however, are not separated by transverse dissepiments, as Gaertner has it. 
The Yuccas with thick seeds and fleshy fruit bear thicker ovules (0.3-0.4 and even 0.5 mm. 
thick), those with thin seeds and capsular fruit thinner ones (0.2-0.25 mm. thick), so that to some 
extent, we may, from the thickness of the ovules in well-developed flowers, guess at the section to 
which the plant may belong., Y. gloriosa and Y. Treculiana, however, have somewhat thinner 
ovules than the others of their section, and in some forms, which I class with Y. jilamentosa, I have 
found them occasionally as thick as these. 
The three carpels are firmly united from the centre of the ovary to beyond the middle; here a 
thin tube, open at the base and top of the ovary, and from this to the external surface a more or less 
closely compressed slit, separate them. These slits open as the fertilized ovary grows, and in the 
fleshy-fruited species eventually form the three inner impressed sides of the six-sided pod. 
The always glabrous ovary is either obtuse and abruptly terminated by the stigma (Y, aloifoliz), 
or it is gradually attenuated into a conical or prismatic glabrous style, sometimes as long as the 
ovary itself (Y. rupicola), which towards the tip.ends in the stigmas, This style is an organ of great 
variability in length and thickness, and may or may not be present in forms of the same species. 
Stigmas we conventionally eall. the terminations of the three carpels, which are distinguished 
from the ovary and-style by their coating of transparent oval or globose epidermidal cells, 
which, however, as already stated, have no stigmatic function, not even that of gathering the [28] 
pollen. . The three stigmas, emarginate or bilobed at the summit, are more or less united, and 
form a tube ;-they are generally erect, but in some species, especially in the true Y. filamentosa, they 
are at last patulous and even recurved. The inside of the stigmatic tube, somewhat triangular in 
