148 THE PLA^T WOKLD 



petals small, twisted at the apex; labellum foiir-liorned at base, the 

 apex folded so as to form a vertical triangular plate. It flowers all 

 summer. This plant is able to grow upright, but in its home, where 

 vegetation is crowded, the flower spike is often pendulous, allowing the 

 curious, grasshopper-like flowers to hang two feet and more below the 

 branch. 



Pseudo-bulbs are, as a general thing, reservoirs containing and 

 retaining the moisture until required; but in the Gongora, as well as in 

 many other of the South American orchids, they furnish a garrison for 

 carniverous ants. There is a hollow pseudo-bulb with either a door- 

 way ready made, or inducements offered to the ants to make one. The 

 result is a perfectly dry, hollow chamber, which, on splitting, shows 

 tiers of cells and galleries. The plants suffer greatly from the depre- 

 dation of cockroaches, their chief enemy, and other pests. In the treaty 

 between the plant and the ants, the latter, in return for a home, destroy 

 the roaches and other insects that attack the leaves of the former. 

 James Rodney in his " Guiana Forest " gives us this experience: Wliile 

 collecting orchids, he saw in a tree overhanging the water, a great clump 

 of Oncidium altissimiim, its graceful flower stem loaded with yellow 

 blossoms hanging over in ever}^ direction. The plant was four feet 

 thick, with panicles rising to a height of twelve feet. He sent one of 

 his boatmen to bring it down. Taking a cutlass, the negro climbed up 

 and began to chop at it, but immediately^ came down with a run, rub- 

 bing his hands and face and picking a swarm of ants from his clothes. 

 Finally they secured the plant, after having been kept at bay for over 

 half an hour, and threw it into the stream, pushing it under water with 

 a long pole. As the roots became soaked, the creek was covered with 

 black patches. Presently larger forms were seen swimming. These 

 were cockroaches. Then came a centipede. It was supposed that the 

 ants had not had time to demolish all of the insects. 



Of Dendrohium there have been several varieties. At present T). 

 nobile is out in full force. Its sheathing leaves are on an upright stem, 

 about one inch apart and alternate, five inches long by one and a half 

 wide. The buds are exactly like those of a lily, if we except a small 

 spur projecting from the under side; flowers in pairs, two inches across; 

 sepals and petals one and a half inches long, from white to deep helio- 

 trope; lip formed like a small calla lily, the edge tipped with rose- 

 purple, the deep heart of royal purple velvet; habit drooping; the stem 

 bearing sixty flowers and over. Suckers or rootlets hang from various 

 parts of the stem. D. Wardianum has dozens of white blossoms edged 

 with rose-purple, with two eyes of gold in the throat. 



In D. fuscatum the deep orange-yellow blooms are two inches 

 across; sepals and petals oblong, somewhat incurved; lip shorter. 



