254 MR. HENRY RIDLEY ON ORCHIDEZ AND 
very thick conical ovary and no pedicel. They are produced in 
pairs subtended by a large dry bract. The lip is remarkably 
small and the globose column narrowed at the top is very 
singular. 
It grows on mangrove trees overhanging the river. 
Denprosium (§ cLAVAT£) TUBERIFERUM, Hook. f., Fl. Brit. 
Ind., v. p. 728. 
Hab. Singapore: Selitar! Toas! 
Pahang: Kwala Pahang ! 
Perak: Gunong Hijan, Murton, fide Hook. f., l.c. 
On trees usually in the low country, local and never common. 
D. (§ CiavaTz) cLavipes, Hook. f., Fl. Brit. Ind., v. p. 728. 
Hab. Pahang: Pulau Chengei ! 
Perak: Scortechint. 
On trees in thick woods, low country. 
T have also received this from Djambi, in Eastern Sumatra. 
D. (§ CLravarz) crumENatum, Sw. in Schrad. Journ., ii. (1799) 
p. 237. 
Hab. Singapore: common everywhere on trees and rocks 
by the sea. Selangor! Negri Sembilau! Perak! 
Johore ! 
Malacca! Penang: Common everywhere in the low 
country ! 
Pahang: Pekan! 
Kedah: Yan! 
Siam: Bangtaphan, Dr. Keith! 
Cochin-China: Saigon, Dr. Haffner ! 
This common plant, known to the residents as the Pigeon- 
orchid on account of the form of the unopened flower, has, like 
some other orchids here, the habit of flowering on particular 
days. At intervals of about nine weeks all the plants in a 
given district burst into flower on a certain day, and as the 
flowers are very conspicuous and abundant, it has a striking 
effect. They are all withered by the end of the day, and no 
more are seen till the next Howering day. Sometimes there 
are a few isolated plants which flower a few days or even weeks 
distant from the others, but far the greater number open on 
the same day. I observed that in Malacca on one occasion all 
the plants flowered on the day before those in Singapore, but 
