Thursday, February 6, 2014

Plant Quiz - Answered

I recently posted the following plant quiz...
Hopefully you haven't forgotten about us here at Get Your Botany On!  Sorry for the long delay between posts.  Here's a quick plant quiz to hold you over until our next more lengthy post.  Good luck!


The Phytophactor answered correctly that this plant is Geocaulon lividum of the family Santalaceae.  Like other members of this family, False Toadflax, as this species is known, is a hemiparasite that produces haustoria that attach to roots of host plants to obtain a portion of its nutrients. 

Geocaulon lividum
Geocaulon lividum is a northern species found throughout much of Canada and Alaska, barely reaching into the contiguous United States.  Because of this geographical distribution, it is a species of conservation concern in several states.  It grows in wet to moist conditions, such as in bogs, fens, and coniferous or deciduous forests, but also on sandy or rocky ridges or dunes near the Great Lakes.  The genus name Geocaulon means "earth" (Geo-) and "stem of the plant" (-caulon), which is a reference to the long slightly subterranean stems (rhizomes).  The specific epithet lividum means "lead-colored," which could be a reference to the flowers, which range from green to purple in color.

Geocaulon lividum
Geocaulon lividum has been treated as a member of the genus Comandra (Comandra lividum), and anyone familiar with the genus Comandra can easily see why.  It differs from Comandra in having green to purple flowers (versus white in Comandra), axillary inflorescences (versus terminal in Comandra), and orange-red fruit more than 7 mm in diameter (versus green to yellowish fruit up to 6 mm in diameter in Comandra).  In each cymule on a Geocaulon lividum plant, the central flower is perfect, whereas the other one to two flowers are staminate; Comandra has all flowers perfect in each cymule.  For comparison, Comandra umbellata is pictured below.  Vegetatively, Geocaulon lividum may be confused with a member of the genus Vaccinium, which would have woody stems and leaves with different venation and texture.

Comandra umbellata
The photographs of Geocaulon lividum above were taken on June 22, 2013 in Copper Harbor, Michigan.  Nice call, Phytophactor!


The Phytophactor said...

Wow, this one is really not an easy one, and my guess is iffy because I've never seen the flowers that purple pigmented (usually green?). Is this Geocaulon lividum, the false toadflax as opposed to the bastard toadflax. But my guess is a pretty rare plant, but the sphagnum is a pretty good clue to the bog habitat.

A.L. Gibson said...

I haven't seen this plant in person and it's quite the lifer for me personally, but I agree with the Phytophactor to this plant's identity. Geocaulon lividum.