186 ORCHIDS OF THE CAPE PENINSULA. 
throughout the genus, to warrant the maintenance of this group as a 
genus. 
§ 2. Eu-disa, is united with the preceding by D. polygonoides (not 
within our limits) and D. cylindrica. It includes several species which 
Lindley placed under his section Repandra. The species, D. maculata, 
D. lineata, and D. cylindrica, are, owing to peculiarities of perianth or 
column, not very satisfactorily referred here, but it appeared undesirable 
to add to sections containing single species. 
§ 3. Vexillata, includes a few species with a nearly flat or concave 
and very erect, odd sepal, and a petaloid appendage to the rostellum 
quite peculiar to this section. 
§ 4. Coryphea, a group of Lindley’s, with subcorymbose flowers and 
low rostellum. The affinity between D. Harveiana and the two other 
species is not very obvious; nevertheless they are connected through 
D. sagittalis. Lindley placed all of these in this section. 
§ 5. Schizodium, established by Lindley as a genus in 1838, has, 
I think, no valid floral character by which it can be maintained as 
distinct from Disa. The structure of the scape in this group is quite 
unique amongst South-African Orchids, and appears to afford a 
maximum of strength with a minimum of resistance to the wind on 
the wind-swept plains where these plants usually grow. It is rarely 
that they are found near the shelter of a bush, or on a mountain-side. 
In D. obliqua two flexures in the scape sometimes succeed each other 
at aright angle. The scape here may be compared with that of the 
still more delicate Carpolyza spiralis (Amaryllidacee), which is doubtless 
serviceable to the plant in the same manner. 
§ 6. Orthocarpa, is formed partly from Lindley’s genus, Penthea. 
It includes five Peninsular species characterised by an untwisted 
ovary, owing to which the flowers assume their normal position (as in 
Satyrium), and in which the odd sepal is usually hooded and reclinate ; 
the flowers usually few and subcorymbose. 
§ 7. Vaginaria, a section of a single species, is adopted from 
Lindley. Its ovary is straight, and it might have been united with 
the previous section; but is remarkable by its singular perianth, 
which resembles nothing else in the genus. 
§ 8. Herschelia, was established by Lindley as a genus in 1888, 
upon the well-known species (H. celestis), D. graminifolia, Ker. I have 
here regarded it as a section, and included also Lindley’s section 
Trichochila (of Disa), chiefly characterised by a clawed lip. It now 
embraces a series of species very variable both in lip and column, and 
sometimes even varying as to the latter in the same species, but all 
agreeing in general habit. The two groups of Lindley are joined by 
such a species as D. Charpentieriana, where the rostellum has three 
teeth, and the gland is single, as in Herschelia; while the lip las the 
