Spring sun is warming south-facing slopes of buttes and hillsides. Snow along Grand Teton National Park roads is finally retreating. Wetlands are warming. Bugs and birds are flying about. The delight is in the details of small flowers; no big show yet.
Along roads and low openings in the valley:
Patches of yellow buttercups are the first to draw the eye.
Buttercup – Ranunculus spp. – flowers gleam, and uniquely so. The outer layer of the petals – epidermis – is only one-cell thick and the cells are particularly thin and flat. They hold pigments that absorb blue-green wave lengths of light. Thus yellow wavelengths can keep going through the outer cell layer, penetrate a thin air layer, and then reach a starch layer of cells that scatters the yellow light back up through the pigments again. Furthermore, the thin outer layer with air layer just beneath has the physical properties of a thin-film, creating the shiny look to the flowers. The combination os pigmentation and unique structural qualities of the flower cells provide the bright glossy yellow found only in buttercups and a few cousins. At certain angles, flowers actually flash a signal to passing pollinators to come visit. (For much more to this complex story see references below.)
Buttercup petals beam intense yellow light and UV wave-lenghs that signal to pollinators. Also, the curving petals with the special cell layers provide addtional warming to the reproductive parts in the center, speeding up the life cycle.
Look closely at our two similar species of buttercups:
The lowest leaf of Sagebrush Buttercup – Ranunculus glaberrimus – is unlobed, the upper leaves are 3-lobed. It is a denizen of sage flats.
Some individual Sagebrush Buttercups don’t have petals, only sepals. I dont’ know why the flashy petals aren’t there.
In Utah Buttercup – R. jovis – both the lower and upper leaves are lobed into three parts. Note buttercups have many separate anthers and stigmas—a common characteristic of this family. It is found in relatively moist locations, including woodland edges and openings.
Springbeauties – Claytonia lanceolata — grow in scattered in patches. Some blooms exhibit obvious pinkish veins that direct pollinators to yellow nectaries in the center. Pollinators bump against the anthers and get dusted with pollen.
It is easy to step on Turkey Peas – Orogenia lineariifolia. The plants look like bits of lichen or stone, nothing to think about.
However, Turkey Peas are more interesting if you take a close look at their tiny white flower with maroon centers that together form clusters barely an inch long. Think about what tiny insects must pollinate them–likey small flies and bees.
Sandhill cranes, bears, and rodents seek out the thumb-sized bulbs (“peas”) for food. (Turkeys would likely eat the bulbs if they lived in Jackson.)
The quintessential western plant Steer’s-head – Dicentra uniflora – requires some belly botany. Scan an area for divided leaves and then get down to stare at the steer-like flowers. This is the larval host plant for the Parnassian butterfly Parnassius clodius, which Dr. Debrinski from MSU is researching in Grant Teton National Park (more info on her research below).
Parnassian butterfly species on Blacktail Butte 5.4.19.
Yellowbells – Fritillaria pudica – are always cheerful! The 6-8”-high plants sprout from miniature scaly bulbs. The base of the 6 yellow tepals is said to change from red to green depending on pollination, but I can’t see any consistent difference happening to the outside flower color or anthers and pistil on the inside. Maybe you can.
Violets are flowering here and there:
Goosefoot Violet – Viola purpurea var. venosa – has leaves shaped like goose feet with a few more toes. The back of the leaves and yellow petals are often purple, hence “purpurea” in its botanical name. Note the dark center of the flower and the convenient landing pad of petals for pollinators.
Several yellow violets intergrade in leaf features which confuse me and other botanists trying to sort out the names. This cheerful specimen is one of three look-alike species – V. vallicola, V. praemorsa, or V. nuttalii. Leaf ratios, shapes, and hairiness, as well as ultimately seed-capsule sizes, determine identification.
Dry slopes and knolls: Rambles up the south side of Blacktail Butte and rocky knolls around Kelly Warm Springs yield treasures tucked into the rocky soils. Many of the plants are silvery and/or hairy and grow very slowly into low mounds or mats—adaptations to limited water and nutrients and intense light and wind.
Please watch you step…these small plants can be hard to see and some are very old.
Hood’s Phlox – Phlox hoodii – is often the first out, with its white to bluish flowers. Bees and flies pick up on the sweet fragrance. They come in and land on the flared petal tips and dip their long tongues deep down the center tube for nectar. They then carry the orange pollen off to other flowers nearby. The leaves of Hood’s Phlox are opposite, very small and tight on very slow growing stems that collectively form a cushion shape. Plants inches wide can be decades old.
Nearby, Twinpods – Physaria didymocarpa – feature bright-yellow, 4-petalled flowers at the end of sprawling 3-4” stems. Spade-shaped, silvery leaves help identify this member of the Mustard Family. Mustards usually have 4 petals, 6 anthers (2 short, 4 long), and one 2-parted pistil.
The first pussytoes to bloom is Low Pussytoes – Antennaria dimorpha. The tiny gray, finely hairy leaves form mats on the ground. Look closely for the flowers.
Individual female flowers have stigmas…
that fork to capture pollen. No males in sight.
Note female and male flowers are on separate plants. This separation helps encourage cross-pollination, but if there are no pollinators present, females can set seeds on their own. Female plants often outnumber male plants in a population.
Sprawling Cymopteris – Cymopteris longipes – is spreading its whorl of dissected silvery leaves low to the ground. As a member of the Carrot Family, plants have umbels, in this case with yellow flowers.
Cymopteris longipes has a buried pseudoscape. This buried stem is surrounded by old leaf bases. The true roots actually branch from below the area shown here.
Later, the underground stem will stretch up lifting the leaves higher to the light above growing competition. The stalk of the umbel will extend, too, elevating the winged fruits into the wind mid-summer.
Pursh’s Milkvetch – Astragalus purshii – is also just beginning to flower on dry knolls. The pea-like flowers are slightly yellow to white with a blue bow to the keel (lower two petals). Some flowers open wide for pollinator business. Note the pinnately divided leaves are silvery hairy.
The brilliant red of paintbrush – Castilleja chromosa – is provided by the leaf-like bracts. Soon tubular flowers will emerge from their axils. I am not sure why there is so much color without the presence of any flowers yet. Maybe the plants are announcing to pollinators: opening for business soon!
Our local Townsendias belong to a beautiful but often confusing genus. This plant has all the features of T. leptotes: narrow leaves, whitish petals, a whorl of 4-5 rows of pointed bracts tinged with color. Apparently this species and T. montana can hybridize or self-fertilize to the point that some experts say separating the two species appears “arbitrary.” I say, let’s just enjoy the flowers if you can find them. They are pretty rare.
Wetlands with catkins:
Shrub swamps throughout the valley are warming up. Ducks, moose, and beaver are moving through the waters under dangling catkins of alders and amidst thickets of pussywillows.
Male catkins of mountain alders – Alnus incana var. occidentalis – elongate: their pollen is released upon the wind to meet up – purely by chance – with the stigmas of female flowers (above left in photo) in separate, stout “cones.”
Later in May, its relative Bog Birch – Betula glandulosa – will bloom after its leaves have filled out.
Male catkin of Booth’s Willow – Salix boothii. Notice the waxy “bloom” on the greenish yellow stem that can rub off. This is a helpful winter ID feature.
Willows (Salix spp.) of various kinds (and there are many) are bursting their buds and producing male or female “pussies”. In willows, female fruits (capsules) are the definitive for identification, but are often elusive. Bees pollinate many willows—they seek out nectar at the base of tiny, petal-less flowers.
A male catkin of cottonwood – note the red anthers that will soon shed pollen.
Cottonwood and its congener aspen (both are in the genus Populus) also have catkins, again males and females on separate plants. It is fascinating to investigate the differences.
We are seeing just the first flurry of flowers. We will try to keep you posted on new arrivals.
Enjoy your adventures into spring!
Frances Clark, Teton Plants 5.7.19
P.S. We always appreciate comments and corrections. Please send an email to tetonplants@gmail.com
References:
“How Buttercups Get Their Gloss” by Stephanie Pappas, Live Science Contributor – link: https://www.livescience.com/57964-how-buttercups-get-their-yellow-gloss.html
“Scientists Discover why buttercups reflect yellow on chins”. By University of Cambridge, Phys.org. December 2011. https://phys.org/news/2011-12-scientists-buttercups-yellow-chins.html
“Functional optics of glossy buttercup flowers” by CJ van der Kooi, et al. Journal of Royal Society Interface 14. Fascinating details including photos of the physics. Available on line at https://royalsocietypublishing.org/doi/full/10.1098/rsif.2016.0933
Dr. Diane Debinski is studying Clodius Parnassia butterfly populations in Grand Teton National Park. Here are a few links to her research:
Teton Plants 