Bluethreads, Yams, and the Fungi Who Love Them

24 Nov


Burmannia biflora


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?”

Burmannia biflora Nov. 22 (JB)

Burmannia biflora Nov. 22 (JB)

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.

Tiputinia by K. Swing.  This is the entire (non-green!) plant behaving like a fungus.

Tiputinia by K. Swing. This is the entire (non-green!) plant behaving like a fungus.

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.

Winged Yam, note how similar the winged flowers are to the winged flowers of Burmannia. (By

Winged Yam, note how similar the winged flowers are to the winged flowers of Burmannia. (By


Posted by on November 24, 2013 in Bluethreads, Uncategorized



5 responses to “Bluethreads, Yams, and the Fungi Who Love Them

  1. Mary Hart

    November 25, 2013 at 4:56 am

    No Burmannia in Uk but plenty of strange plants indulging in symbiotic and parasitic relationships. Of the latter my favourite is mistletoe, which is abundant here in Herefodshire and Worcestershire, especially on poplar trees. Much used w. Holly as Christmas decorations.

    • George Rogers

      November 25, 2013 at 8:12 am

      Hi Mary, Yes, I’m fascinated with mistletoe. Although you don’t see it growing wild right here, there is a cultivated tree just outside the building where I work which obviously came from some distant plant nursery bearing mistletoe. The mistletoe has expanded to a large mass and presently is in full berry getting ready for the Holiday Season.

  2. Mike Y

    November 26, 2013 at 8:34 am

    Hey George, I think mistletoe is now invasive in northern Florida. You can really see it this time of year on deciduous trees.

  3. George Rogers

    November 26, 2013 at 9:25 am

    Thanks Mike, Would love to know the origin of the mistletoe on the tree outside my office. Wonder where they trucked that tree from.

  4. Mike Y

    November 26, 2013 at 10:46 am

    Doing a quick google search it is listed as a noxious weed in California and seems to have naturalized throughout the southeastern United States


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