10 December 2009

Snowball Saxifrage

A somewhat common plant that we saw in the alpine life zone in Colorado was Snowball Saxifrage (Saxifraga rhomboidea), a member of the family Saxifragaceae. This species grows in a variety of habitats from the foothills (6000' - 8000' above sea level) all the way up into the alpine (>11,500' above sea level) (Guennel 2004). It is known from many states in the western part of the country (USDA NRCS 2009). Edward Greene made the first collection of this species in 1889 and named it Saxifraga rhomboidea; John Small came up with the name Micranthes rhomboidea - the name currently used for this plant by William Weber - for the same species in 1905 (Southwest Colorado Wildflowers).

Also known as Diamondleaf Saxifrage and Early Saxifrage, this species can often be found in rocky habitats. This is one potential origin for the genus (and family) name, as "saxifrage" is translated to mean "rock-breaker;" another potential origin, as discussed by Gerard in The Herbal (1633), is that plants in this family have been used for hundreds of years to treat kidney stones (Weber 1976; Southwest Colorado Wildflowers).

I took the photograph above at Loveland Pass on the Continental Divide in central Colorado.

Guennel, G.K. (2004). Guide to Colorado Wildflowers, Volume 2: Mountains. Englewood, Colorado: Westcliffe Publishers.

Southwest Colorado Wildflowers. Retrieved December 10, 2009. http://www.swcoloradowildflowers.com/.

USDA, NRCS. (2009). The PLANTS Database (http://plants.usda.gov/, 10 December 2009). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

Weber, W.A. (1976). Rocky Mountain Flora. Niwot, Colorado: University Press of Colorado.


Justin Thomas said...

What is going on with Weber and the names he uses? Really, does anyone know? Is he crazy or is he dangerous?

Scott said...

I don't know, but it can sure make field botany more difficult. For what it's worth, Micranthes has long been treated as a section of Saxifraga.

I found a paper from 2000 at http://hua.huh.harvard.edu/china/novon/Gornalletal10-4.htm that talks about distinguishing Micranthes from Saxifraga for the Flora of China. It states, "the segregation of Micranthes from Saxifraga is justified on the basis of certain morphological differences (described by Webb & Gornall (1989) and summarized in Table 1) as well as gene sequence data (Soltis et al., 1996 and pers. comm.). Here are the characters shown in the Table 1 that they reference...

Micranthes has reticulate pollen exine, 1 integument, a seed surface that is usually longitudinally ridged with ribbonlike or pectinate ribs, carpel placentae that are united for less than half of their length, and a usually leafless flowering stem. Saxifraga has variously striate pollen exine, 2 integuments, an unribbed seed surface, carpel placentae that are united for more than half their length, and usually leafy flowering stems.

It seems that Weber is an extreme splitter using whatever published works he can find to divide genera (and families) as much as possible.

MartyL said...

Hey Scott - thanks for bringing out your alpine adventure pics to brighten things up a bit now that the dark days are upon us. It's been awhile since I've been on a nice alpine meadow -- too long. If you ever get a chance, check out Mt. Rainier's aptly name Paradise. Amazing!

Scott said...

Hi Marty. Glad you're enjoying the alpine photos. I've got plenty more that I will post throughout the winter.

I looked at the link to Paradise... looks like an amazing place. I'll put it on my long, growing list of places to visit.

Ted C. MacRae said...

Lovely plant. Too many places to see, and only one life to do it!

Scott said...

I hear ya, Ted.