O E C H I D S OF THE SLEEIIF.HIJIALARA,
The spur is in tliis species distinctly divided into two unequal antero-posterior
chambers for a short space near the n^oiith by a horizontal plate which (as shown
in figs. 3 and 4) proceeds from the anterior callus. The spur is also constricted below
tins plate, and about its middle, by tho calii which project from its back and front walls
and almost divide it into fin upper and a lower section. In those respects tliis is not
a true SaccohUum, as that genus is understood in this work, there bemg in the
spuj of SaccoMium neither callus nor septum. Nor is it a true Cleisostoma, the spur of
which genus is occluded not only by antero-posterior calli, but sometimes also by a plate
proceeding from tlie back wall. Neither is it a Sarcanthus, in which genus there is,
besides calli, a vertical antero-posterior septum dividing the spur into two lateral
chambers. In fact there is as much justification for making this the type of a now
genus as thei-e was for the formation of Ckmstoma as a genus; for the presence of
a horizontal plate (forming a small chamber) on the anterior wall is of as much
importance as the presence of a plate on the posterior wall. But, on our opinion,
there are already too many genera in this neighbourhood. We therefore leave this
plant in Saccolalmn, where it is placed by Dr. Reichenbach and Sir Joseph Hooker,
beiBg in entii-c agreement with the remark of the latter distinguished botanist (Fl.
Br. Ind. VI, pp. 66, 71) that, but for the undesii-able dislocation of synonymy which
would result, it would bo better to reduce both the genera Cleisostoma and Sarcanthus
to Saceolabium.
PLATE 306.—^acco^nli'im Mchromtim, Eeichb. fil. Part of a plmt, of natural sism. Fig. 1 a flower,
2 stalied ovaiy, column with anther m si(u, aad lip, 3 longitudinal section of colmtm and spur,'
4 transTerse seotioa of spur aboTe tho middle, 5 lower surface of empty anther, 6 poUinia in siiu
on tie apex of tlie column, 7 the same removed; aH enlarged.
52. Cleisostoma, Blume.
Epiphytes without pseudo-bulbs. Sims more or less elongated, leafy. leaves
coriaceous or fleshy, flat or semi-terete. Injloreseence leaf-opposed, racemose or paniculate.
Sepals and petals adnata to the column, spreading, sub-equal. Lip sessile on the footless
column, the base with a large saccate or infundibuliform spur, sometimes dilated
at the apex, its cavity more or less closed by two calH the posterior of which is often
bifid, and sometimes also by a dorsal scale, but never by a septum; the lateral lobes
small or absent; the apical lobe thickened, concave. Column short, thick, with no foot.
AntUr depressed; pollinia two, often bifid; caudicle single. Species about 40; Eastern
Asiatic and Austi-alian.
Ca-vity of spur occluded by two calli, the dorsal one divided at the
apes into two Bcale-Hke plates.
Leaves semi-terete, ohamieUed in front, their apices acute and
fiub-spinous J. c-, armgerum.
Leaves flat but keeled.
Spur widely saccate, not dilated at tho apes; apical lobe
of lip triangular-hastate, its apex narrow and bifid; apices
of leaves acute 0. brevipes.
Spur infundibuliform, dilated Mid notched at the apex; apical
lobe of lip thick, triangular-ovate, acute, entire; apices of
leaves broad, obliquely bifid S, C. tpicatum.
CLEISOSTOMA. 23 1
Mouth of spur occluded by two calli m d by a semi-circular erose scale
on the cohunn; leaves broad, obtuse and obliquely bifid at the apex . i.. 0. Weiidlandorum.
Spur with rather thin calli, its moutli closed by a scale from the
posterior wall 5. 0. lambusarum.
Posterior callus of spur not bifid; dorsal or columnar scale none.
Apical lobe of Hp fleshy, convex, its edges erose; spur wide,
saccate, blunt 6. C. mkranihum.
Apiaal lobe of lip concave, its edges entire; spur narrowly
cylindric C. gemmalum.
1. CLEISOSTOMA AKMIGEHUM, King and Pantling in Joum. As. Soc., Bengal,
Vol. LXV, pt. 2, p. 123.
Sierns erect, rigid, 2 to 4 in. long. Leaves very fleshy, semi-terete, channelled
in front, the apex sub-spmous, not narrowed at tho sheathing wrinkled base. Racemes
oxtra-axillaiy, -5 in. long. Floioers crowded, -25 in. across. Sepals spreading, ovaterotund,
apiculate. Petals much smaller, also spreading, oblanceolate. Lip with a wide
sacciform spur half as long as and parallel to the ovary, its edges mth broad shallow
tiiangular side lobes; apical lobe ovate, blunt, concave; the interior of the spur with
opposing thick calii £i-om the posterior and anterior walls, the latter much the larger
find occluding the passage; the dorsal callus curved and dilated upwards, its upper
surfacc produced into two broad scale-like teeth pointing outwards. Column short,
adlierent for half its length to the lip. Anther depressed; rostellum beaked; pollinia
two, globose, bifid; caudicle stout, thickened at its junction with the pollinia; gland
with two ovoid lobes with decm-ved margins.
Silvkim, at low elevations, common; in flower during September; Pantling No. 252.
The flowers are pale straw-coloured, flushed with pink. A coloured drawing of this
has been in the Calcutta Herbarium since 1856, but until recently there have been no
specimens, the original from which that di'a-ndng was made having been lost.
PLATE Z09,.—Ckitosicttia armigoi-um, Emg and Pantlhig. A plaat. Fig. 2 transverse section of a
leaf, 0/ natural size. Tig. 1 a flower, 3 side view of floral bract, ovary, column, anther in situ and lip,
4 transverse section of spur below the calli, o the posterior callus inside the spur, 6 longitudinal section
of tie ovaiy column and spur, 7 under surface of anther, 8 poUima-iii/fl and hack viem; all enlarged.
2 . CLEISOSTOMA BEEVIPES, Hook. £1. Fl. Br. Ind. VI, 73.
Stems about as thick as a goose-quill, branching, pendulous, 8 to 16 in. long.
Leaves thickly coriaceous, wrinkled, narrowly oblong-lanceolate, acute, not narrowed at
the sheathing base ; length 2-5 to 3-5 in., breadth -4 to -5 in. Spi/ccs extra-axillary,
much shorter than the leaves, pendulous, the rachis very stout, the pedicel short.
Flowers crowded, -4 m. in diam. vertically; Jloral tract broad, sub-acute, short. Sepals
sub-equal, broadly ovate-elliptic, sub-acute, the dorsal somewhat concave. Petak oblanceolate,
blunt, shorter than the sepals. Lip longer than the sepals, the base forming a
short wide sac almost at right angles to the ovary, its mouth with triangular falcate
side lobes; apical lobo fleshy, elongate, triangular-hastate with a narrow aristately bifid
decuiTcd opcx. Column stout, with a large bifid callus at its base, hispid on the
anterior surface and projecting into the spm- to meet the thick callus on the anterior
wall, and thus closing the oiiflce of the sac; dorsal scale none. AniJier depressed,