plant phenology in the Presidentials (particularly Prenanthes), please PM

If any of you are out in the higher elevations of the Presidential Range in the WMNF this week, or have been there the last few days, I would greatly appreciate knowing whether the Boott's rattlesnake-root (Prenanthes boottii = Nabalus boottii) is in bloom yet, as I have to do a plant survey at one of its stations.

This is a small white-flowered plant that's related to asters and dandelions, found from 4500-5500ft elevation in gravelly areas with moderate shelter from the wind:



The easy distinguishing characteristics are deer-hoof-shaped leaves, white composite flowers with ray flowers only, which are usually a nice bright white and more than 12 rays per flower head. The other alpine rattlesnake-roots almost always have at least 1 leaf divided into lobes, and tend more towards a cream-color with fewer rays.

Unless the flowers are out, it is not possible to be sure which species it is; they weren't in bloom at one site last Mon 7/16, and probably by early August it will be too late...

(please don't post specific locations online; PM me instead if you can share more details)

I was on the Huntington Ravine Trail last Thursday and took this picture. The leaves look like the ones you describe, but the flower petals don't look the same. Never-the-less, I'm no botanist, so I'll let you judge.

peakbagger-paul said:

I was on the Huntington Ravine Trail last Thursday and took this picture. The leaves look like the ones you describe, but the flower petals don't look the same. Never-the-less, I'm no botanist, so I'll let you judge.

Click to expand...

I may have the name jumbled, perhaps it is three toothed cinquefoil. (I don't have aguide with me at the moment) I saw them on Nelson crag and Glenn boulder this weekend.

Puck said:

I may have the name jumbled, perhaps it is three toothed cinquefoil.

Click to expand...

yup. (aka Potentilla tridentata = Sibbaldiopsis tridentata)
Common in alpine & subalpine habitats.

edit: I was scratching my head on this one.... of the two photos I showed, the left one shows the leaves of Prenanthes boottii (the larger leaves) along with the three-toothed cinquefoil. Sorry for the confusion & thanks, as this lets me know I should take another picture of the rattlesnake-root that doesn't show other plants in the vicinity.

btw, I think I have got the info I needed.

edit again: ack! both my photos show cinquefoil leaves! I'll probably have to wait until next year to get good photos.