This is a thorny currant that grows at middle and upper elevations called gooseberry currant (Ribes montigeneum). It grows in western North America, and a pretty pink flower blooms in spring and early summer. Later a red berry appears that is sought after by wildlife.
For more info about gooseberry currant, click here.
Here's another penstemon, this one clearly different from yesterday's in the way the flowers line up and down the petiole. This smoothleaf beardtongue (Penstemon leiophyllus variety francisci-pennelli). This variety is found only in Nevada and above 8,000 feet. The species is only found in Utah and Nevada. The stem is glabrous (smooth) and the corolla slightly hairy.
There isn't much info out there about smoothleaf beardtongue, but you can see the USDA Plants profile if you click here.
We have a lot of penstemons in the area, and I believe this one is low beardtongue (Penstemon humilis). The flowers are dark blue with a white interior, the stems are slightly hairy as is the corolla, and the calyx is shorter than the corolla tube, and the staminode is hairy at the apex. My only problem is that the photos I see on the internet show taller plants with more flowers per petiole, so if anyone has a different i.d., please let me know.
It's found from about 6,000 to 11,000 feet and blooms mid-summer. For more info about low beardtongue, click here.
This fairly common yellow flower with four petals and four sepals is western wallflower (Erysimum capitatum), a member of the Mustard Family (Brassicaceae). It grows at a wide variety of elevations.
It can grow from 6 to 36 inches high, and flowers throughout the summer depending on the elevation.
For more information about western wallflower, click here.
This attractive plant that grows on limestone soils from 6,500 to 11,500 feet is pink alumroot (Heuchera rubescens), a member of the Saxifrage Family (Saxifragaceae). It is found in the Intermountain West.
The pink flowers are small, with white at the tips and are found branching off long petioles.
There are a lot of Mustard Family (Brassicaceae) nonnatives, and today we're going to add another one, watercress (Nasturtium officinale). Watercress grows on water, and in fact requires it--the presence of watercress shows that the water is present year-round. Most of the year only the leaves are present, but right now it is producing some four-petaled flowers.
Watercress is a common food for ducks and deer. It can even be eaten by humans, although due to parasites, you should either disinfect it or eat the watercress you can buy at the grocery store.
This is a high elevation plant, hoary groundsel (Packera werneriifolia). It's a member of the Sunflower Family (Asteraceae). I took this photo early in the season (June 2009), so the ray flowers still hadn't emerged. The plant doesn't grow particularly tall due to the harsher alpine climate conditions.
Another common weed around my house is prickly lettuce (Lactuca serriola), a member of the Aster Family. It is native to Europe but now found through much of North America. It reproduces by seeds.
The flowers are yellow, with indentations on the ray flowers.
Each plant can have many flowers and even more seeds.
Continuing with the theme of weeds around my yard, today we've got field bindweed (Convolvulus arvensis), also called morning glory. It's a member of the Morning Glory Family (Convolvulaceae), and although it's common throughout North America, it is not native and many states consider it a noxious weed. The pretty flowers that open daily grow along a vine that quickly entangles itself around other vegetation, fences, and whatever gets in its way.
One of the weeds that I find all too frequently in my garden is common mallow (Malva neglecta), a member of the Mallow Family (Malvaceae). It has deep roots, so I have to pull hard to remove it.
Each stem supports multiple leaves and some rather pretty flowers. It is native to Europe but has become a weed in most of North America.
This long-blooming white flower with the papery thin flower petals and the prickly stems and leaves is flatbud pricklypoppy (Argemone munita), the only member of the Poppy Family (Papaveraceae) in this area. It is native to the western United States and grows often in disturbed areas, such as along roadsides.
Nestled among the white petals is a yellow clump of 150-200 stamens, with a maroon stigma appearing right in the middle. 
The flower buds are also prickly.
Here's a closeup of some of those prickles on the stems and leaves. They deter animals from eating this plant.
This striking magenta flower found at higher elevations and often near water is Parry's primrose (Primula parryi), a member of the Primrose Family (Primulaceae). 
Most of them have finished flowering for this year, leaving the leafy vegetation behind.
But I looked all around and managed to find a few flowers still hanging on. This flower lends so much color to the sub-alpine and alpine scenery. It also stands out because it is so large compared to much of the higher elevation vegetation, much of which has shrunken in size to deal with the harsher growing conditions.
This dainty Pea Family (Fabaceae) flower is spiny milkvetch (Astragalus kentrophyta). It grows above 10,000 feet in elevation, and is native to western North America. It has pointy leaves that somewhat resemble spikes.
This beautiful bush growing in limestone areas is desert sweet (Chamaebatiaria millefolium), more commonly called fern bush. It's a member of the Rose Family (Rosaceae) and is native to the western United States.
The flowers look like most other rose-family flowers, with five petals. The leaves are quite fern looking, with many leaflets (hence the species name millefolium).
Seeing goldenrod in flower is bittersweet--it's one of those flowers that appears at the end of summer, and you know that it won't be too long until the cold creeps in. This species grows in dry areas and is Threenerve Goldenrod (Solidago velutina), a member of the Sunflower Family (Asteraceae). It's native to the western United States.
This showy aster growing in moist places is Eaton's aster (Symphyotrichum eatonii), formerly Aster eatonii. It's a member of the Sunflower Family (Asteraceae). It is native to western North America.
The disk flowers are yellow, while the ray flowers are pinkish-whitish.
Growing next to a stream I noticed leaves that were a notched semi-circle with even dentations all around the edge. Rising from these leaves was a slender stalk and delicate, small flowers. This was brook saxifrage (Saxifraga odontoloma), also called streamside saxifrage. It is native to western North America.
The flowers have five petals with a two-beaked pistil and ten reddish anthers.
This large plant growing next to a stream was a little bit of a mystery at first, because it had already flowered and only had strange looking fruits on it. The leaves were large and split in three leaflets. A little searching showed it was a member of the Rose Family (Rosaceae) called largeleaf avens (Geum macrophyllum). It's native to western and northern North America.
Flowers appear in June and July, but by August only the seed is left.
Unless you get lucky and catch a few petals still clinging on!
The flowers on this two-foot tall plant are small, so they might not attract your attention at first, but they are one of the few pink flowers blooming this time of year. They arise from a basal rosette of leaves that help identify this plant as a member of the Buckwheat Family (Polygonaceae). This is redroot buckwheat (Eriogonum racemosum), with many other common names, such as wild buckwheat. It's found in the desert southwest.
The flowers have six petals and are close to the stem.
