Friday, April 8, 2011

hill star ~ 04/08/11 ~ Garland Ranch



hill star
Lithophragma heterophyllum
Saxifragaceae

Oy! It's taken me a while to figure out which species this is as several Lithophragma flowers look exactly alike with small, white, fringy flowers on long stalks. A few years ago, I even wondered if the color of the stalk, green or red, had anything to do with the different species. Nope.

Thanks to multiple sources, there are only two species recorded for Garland Ranch, L. heterophyllum and L. affine (commonly known as woodland star; please note other species are also called this). At our recent wildflower show, a very friendly volunteer overheard my conversation with my companion as I was describing my confusion between the two. She pointed out differences in the leaves, with one being roundish and the other being deeply lobed to the point of looking spindly. I thought, "Aha!" Again, nope. As you can see from my 2nd and 3rd pictures above, there's a variety of leaf shapes found on the same plant.

However, after researching this, including looking up Jepson's descriptions, I would have assumed the plant samples were inadvertently switched, except that my pictures from the wildflower event clearly show what I now consider a more reliable distinction: L. heterophyllum has a squarish calyx base (bell-shaped or U-shaped), whereas L. affine has a tapered calyx (obconic or V-shaped).

Are you confused, yet? I am and may have to review/edit this later and make sure I got it correct.

7 comments:

Out on the prairie said...

The jagged petals are unique. I have been in the woodlands more looking for these spring beauties

Nature ID (Katie) said...

Steve (I'm assuming that's your name), I don't believe you'll find this genus at all in Iowa.

Cindy said...

Your photos or the labels at the show may have been switched? One of our docents told me how she tells the diff between Hillside star (L. heterophyllum) and woodland star (L. affine). The flower on HILLSIDE star has a cup that is smoothed flat on the bottom like your bottom would be if you slid down a HILL. You can even see this "flat bottom" in the Calflora L. heterophyllum photo you linked to. The cup on the bottom of woodland star is pointed. Works everytime now when I flip the flower over to check. Docents rock!

James said...

This is a plant where believing the distribution data can sometimes blind you from seeing a rare plant. I was on a hike last year when we saw some of these hill stars. People had looked at them casually over the years and called them woodland stars, but a botanist a few seasons earlier had bothered to key it out and found this patch that was actually hill stars, the first documented occurrence in my county.

Nature ID (Katie) said...

Thanks, Cindy. Despite what the docent told me, I found leaf shapes to be unreliable when determining the ID between the two species. I like your analogy about the cups; it serves as a confirmation of what I've already written above in the last paragraph.

James, I don't key, so I have never claimed to to have proper IDs all the time. I try my best based on information that is rarely found in official keys. I guess that's becoming the point of my blog... to ID based on photographs and descriptors that can quickly clarify the difference between species in the field.

GretchenJoanna said...

I've never seen anything like those fringed flowers, and I just stopped to say they are very special!

Nature ID (Katie) said...

OK, I need to admit I was incorrect in my comment above. There are Lithophragma in much of the western US: http://www.swcoloradowildflowers.com/White%20Enlarged%20Photo%20Pages/lithophragma.htm