I encountered few insects this past June on the dry slopes of sand shinnery oak shrubland that just makes it into the northwestern corner of Oklahoma’s Four Canyon Preserve – insect population levels were still depressed from the wildfire that swept through the area in April of last year. Plant life, however, was diverse and abundant, including this most unusual plant – Krameria lanceolata (many common names, including trailing krameria, trailing ratany [sometimes spelled “rhatany”], Texan ratany, prairie sandbur, sandspur, etc.). A dicot in the monogeneric family Krameraceae, plants in this genus share several unusual traits, the most obvious being their distinctly orchid-like, zygomorphic flowers (i.e., capable of division into symmetrical halves by only one longitudinal plane passing through the axis). The resemblance to orchids is strictly superficial – they are most closely related to plants in the family Zygophyllaceae.
Orchids, of course, are monocots with trimerous flowers that only appear to be five-petaled because of the three petal-like sepals and the third true petal being modified into a “lip” onto which pollinating bees land. Krameria flowers also appear five-petaled with a lip, but in this case it is the five sepals that form the “petals,” while the five true petals are modified into a lip (three fused petals) and two lateral upright “flags” called elaiphores. These eliaphores play a central role in Krameria‘s unusual pollination biology, whose flowers produce not nectar, but fatty oils as rewards for their visitors – female bees of the genus Centris (Anthophoridae) (Simpson and Neff 1977). The bees collect the oils from the modified external surfaces of the eliaphores, pollinating the flower in the process, and mix the oils with pollen to feed their larvae. Although the Krameria plants are wholly dependent upon Centris bees to effect their pollination, the relationship is not mutually exclusive – Centris bees utilize other oil-producing plants as well.
All species of Krameria examined to date are obligate semiparasites, forming haustoria on the roots of a broad range of host plants. Of the 18 species currently known in the genus, five occur in the U.S., with K. lanceolata the most widespread (Kansas and Colorado south to Arizona, New Mexico, and Texas and east to Georgia and Florida) (Austin and Honeychurch 2004). It is distinguished from the other U.S. species by its herbaceous, prostrate form.
Update 8/10/09: Mike Arduser, my hymenopterist friend who visited Four Canyon Preserve with me, wrote the following in response to my query about collecting bees from these flowers:
Yes, collected several off Krameria at Four Canyons and at Packsaddle – all were the same species, and I’m trying to remember the name as I’m writing this (all notes and material are at home) – it was Centris lanosa. They are best found by listening, as they have a distinctive buzz as they move from flower to flower at ground level (difficult to see there).
Austin, D. F. and P. N. Honychurch. 2004. Florida ethnobotany. CRC Press, Boca Raton, Florida. 909 pp.
Simpson, B. B. and J. L. Neff. 1977. Krameria, free-fatty acids and oil-collecting bees. Nature 267: 150-151.
Copyright © Ted C. MacRae
11 thoughts on “Friday flower – Krameria lanceolata”
A very interesting flower. Did you find any bees visiting the flowers?
Best regards, Trevor
Hi Trevor – unfortunately, I did not get a chance to see the bees. I’ll have to ask my hymenopterist friend who was there with me if he saw them.
That’s a beautiful close up. It shows all of the details of the flower perfectly.
Thank you, Misty.
Great photo and writeup as usual.
I have always thought that this was an overlooked and much unappreciated flower/plant.
You do a great job on plants and habitat as well as insects and other critters.
I have been enjoying your great photos from the new camera.
Hi Troy – I appreciate your kind remarks, but the new camera really has made it easy for me.
As my Grandmother would say, ‘Horse radish’ !
Good equipment helps,
Good subject matter helps,
But it’s the Photographer who finds, composes, photographs, processes, and publishes.
You do great work, and your writing is exceptional.
Well, thanks Troy. I humbly accept your praise 🙂
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Deadly thorn seed the size of a dime. The thorn seed sticks to tires and spreads. This is a highly invasive species. Beware, don’t start it on your property. Hard to get rid of.
You must have this plant confused with something else. Krameria lanceolata seeds may be spiny, but the spines are too soft to puncture a bare foot, much less a tire. This species is native to the southern U.S. and is not at all invasive. See Wildflowers of the Western Plains: A Field Guide.