Excerpts from Jim Conrad's
Naturalist Newsletter

from the January 26, 2007 Newsletter issued from Sierra Gorda Biosphere Reserve, QUERÉTARO, MÉXICO
ORCHID OUT ON A LIMB
Being so deep into the dry season, not much is blooming here other than the Sweet Acacias I told you about, and ornamentals planted and watered in people's yards. Still, the other day I was really tickled to find a cluster of epiphytic orchids growing on the completely leafless limbs of a tree next to the lake. You can see it below:

LEOCHILUS ONCIDIOIDES

The plant was past its flowering peak, its few remaining white blossoms faded and drooped. Still, in the lower, right corner of the above picture it's nice to see one of the plant's fruits. Also, if you look closely you can see the white roots that are so helpful in distinguishing orchids from other epiphytes such as bromeliads and ferns. Finally, at the base of the left-most leaf you can see that the flat blade connects at an articulation point with a swollen, green, football-shaped item known as a pseudobulb. Pseudobulbs are storage organs for water and photosynthesized carbohydrate. Most orchid species don't have pseudobulbs, so these structures are very helpful in orchid identification. And that's good, since the Orchid Family is the largest of all flowering-plant families; distinguishing its ±20,000 species can be a challenge, especially when you're identifying wild species in a country without fieldguides.

This looks like LEOCHILUS ONCIDIOIDES, occurring from central Mexico south into Honduras. The Flora del Bajío says that the species is scarce in this region, thus vulnerable to extinction here in upland central Mexico.