CXXXIII. ORCHIDEÆ (ROLFE). 13 
so-called disc or central part usually bearing crests or appendages, and 
the base sometimes extended into a sac or spur. Stamens and style 
united into a central column which faces the lip. Anther (in the 
African genera) solitary, on the top or back of the column, and more 
or less adnate to it, 2- or 4-celled. Pollen-grains cohering in 2-8 
globose or club-shaped, waxy or granular masses, called pollinia, which 
are free or cohere in pairs or fours or altogether by a viscid append- 
age, and sometimes attached to a distinct stipes and gland. Ovary 
inferior, 1—-celled with parietal placentas in the African genera, undeve- 
loped at flowering-time. Stigma either consisting of a viscid surface 
near the top of the concave side of the column or two-lobed and lateral ; 
in the former case it faces the lip, and is usually separated from the 
anther, below which it lies, by an appendage called the rostellum. 
Seeds very numerous, minute, fusiform ; testa loose, reticulated, enclos- 
ing a homogeneous embryo.—Herbs of various habit, or rarely 
shrubby ; in many cases terrestrial, with tuberous roots or perennial 
creeping rhizomes, annual herbaceous stems and solitary spicate or 
racemose flowers, or in other cases epiphytal, with perennial stems 
or branches, variously thickened and forming pseudobulbs, upon which 
the leaves and flowers are borne, or the latter sometimes produced 
below them. Leaves alternate, simple, entire, coriaceous or mem- 
branous. Inflorescence terminal, basal or axillary, spicate, racemose 
or paniculate, sometimes single-flowered. 
The largest order among monocotyledons, the species now known being estimated 
at over five thousand. They are found throughout the globe, except in the highest 
latitudes and altitudes, and the more remote oceanic islands. The epiphytic species 
are for the most part confined to the intertropical zone, within which they are most 
numerous in the mountains of Tropical Asia and America; in Tropical Africa, 
however, the majority of the species are terrestrial. 
Pollinia waxy. 
Anther 2-celled; pollinia 2-8, united by a viscid 
appendage, free from the rostellum + Tribe 1. EPIDENDREÆ. 
Pollinia 4, sometimes cohering in pairs. 
Column not produced into a foot at the base ; 
lip continuous with the base of the column; 
flowers with spreading perianth segments Subtribe i. Mats, 
Column produced into a foot at the base; lip 
articulated to the foot of the column; 
flowers with erect or subconnivent peri- 
anth segments . ; S : . Subtribe iis DENDROBIEÆ. 
Pollinia 8. 
Column produced into a very short foot at the 
base; lip attached to the foot of the 
column; subsaccate at the base . Subtribe iii. ERIEÆ. 
Column footless ; lip inserted at the base of 
the column, and either convolute round 
it or more or less adnate to it; its base 
produced into a slender spur ` Subtribe iv. BLETIER. 
Anther cells usually confluent ; pollinia 2 or 4, 
attached singly or in pairs to a stipes and 
gland (a process of the rostellum), with which 
they are carried away upon removal. . Tribe 2. VANDEX. 
