Friday John and George took a late-November look at Jonathan Dickinson State Park and came upon a remarkable species, Burmannia biflora. The entire plant consists of one or more lilac flowers teetering on a thread-thin unbranched green stem four inches tall. The leaves are so tiny as to go unseen, in other words at first glance the plant is a flower on a thread so skinny it is surprising the thread can hold up the blossoms.
This link shows clearly the nearly leafless plants rising from the ground. CLICK
Inquiring minds want to know, “how does that skinny little “leafless” waif photosynthesize enough to support itself…don’t plants need leaves for that?”
Some plants derive some or essentially all of their nutrition from sources other than photosynthesis supported by root-absorbed minerals. Some species are parasitic on other plants. Others are carnivorous, although these obtain mainly nitrogen from their “meat” so still must photosynthesize. Most plants have symbiotic relationships with underground fungi, getting some of their mineral “fertilizer nutrients” from their fungal associates. And now to get to the point, a few plants take the fungal relationship even further and derive so much substantive nutrition from symbiotic fungal partners that their photosynthetic needs and capacity dwindle, and sometimes disappear altogether. They become saprophytic by symbiosis, flowering-plant pseudo-fungi.
The Burmannia Family is known for that. You might see the family as an assortment of mostly (or all?) fungally nourished species, some with merely partial photosynthetic ability and others 100% on fungal life-support. They become nutritional extensions of their fungal partners.
The Ecuadorian species shown below, Tiputinia foetida, unknown until 2005, is obviously completely non-photosynthetic. There are many additional examples in the Burmannia Family.
The nutritional relationships of our local Burmannia biflora are, to my incomplete (!) knowledge, not well known and would make a fascinating study. The plants have some photosynthetic ability, apparently supplemented by a fungal support staff. The roots are thick, shallow, sparse, and coarsely branched, probably a reflection of fungal symbiosis. (Look at the root on Tiputinia above.)
In some or all members of the Burmannia Family the roots lack the internal layer known as the endodermis characteristic of “normal” roots with normal nutrient uptake by absorption. Apparently Burmanniaceae roots don’t absorb in the conventional fashion.
Another oddity of some Burmanniaceae species is a spongy sheath called a velamen, much better known as a feature of the Orchid Family. Burmannia and its relatives were once erroneously thought to be kin to Orchids. DNA shows them to be more closely related to yams. But who needs DNA for evidence? Compare the wings on the flower bases of Johns’s Burmannia photo above to the similar winged flower bases on many yams, including our own weedy Winged Yam.