Ruellia and Blechum it is clearly distinguished both by its 
inflorescence, calyx, and ovarium. From Lepidagathis it 
differs in‘its calyx, in the regularity of its corolla, and very 
much in habit. /&theilema, or Phaylopsis, to which it may 
be considered most nearly related, is characterised by the 
large size of the dorsal lobe of its calyx, and by the uni- 
formity of the other divisions, and, moreover, by its being 
5-parted only, not distinctly 5-leaved, with glumaceous 
sepals overlapping each other. The fruit of Geissomeria is 
unknown. Its pollen is remarkably large, cylindrical, with 
rounded ends, and smooth. We are not prepared to state 
the value of this curious character; but it may possibly be 
common to several. genera of the order. The pollen of 
Acanthus mollis has certainly the same figure, but is rough, 
not smooth. 
Stem erect, round, slightly downy. Leaves opposite, 
ovate-lanceolate, wavy, sessile, tapering to the base, smooth 
above, somewhat pubescent beneath, silky at the veins. 
Spikes terminal, and axillary, leafy at the base, closely 
imbricated. Bractee 3, ovate, nerved, ciliated, downy, 
the exterior one twice as large as the two lateral ones. 
Calyx 5-leayed, glumaceous, smooth, ciliated, with unequal, 
imbricating sepals, of which that at the back is the largest, 
and those which are most interior are the smallest. Corolla 
scarlet, tubular, velvety, with an arcuate, clavate, some- 
what ventricose tube, which is smooth inside; the limb 
erect, 4-fid, the upper lobe rounded, transverse, ovate, 
emarginate, the others entire, the lateral ones being smaller 
than the lowest, which is bearded. Stamens 4, nearly 
equal, the length of the tube, towards the base of which 
they are inserted. Jilaments filiform, dilated at the 
base, hairy inside, densely villous at the base. Avthers 
linear, two-celled, cohering by their acute hairy apices. 
Particles of Pollen unusually large, cylindrical, rounded at. 
each end, quite smooth, three times as long as broad. 
Ovarium ovate, tapering, somewhat stalked, with 2-seeded 
cells. Style filiform. Stigma funnel-shaped, with a hairy 
line on one side. ia 
