BLM Idaho

Plants of the Boise Foothills

brochure BLM Idaho - Plants of the Boise Foothills

A Field Guide to Plants of the Boise Foothills. Published by the Bureau of Land Management (BLM).

A Field Guide to Plants of the Boise Foothills i ii Acknowledgements This field guide evolved through discussions of its need and usefulness with members of the Healthy Hills Initiative. It quickly developed into a group effort. Special thanks go to the following entities: Ada Soil and Water Conservation District Healthy Hills Initiative Southwest Idaho Resource Conservation and Development Council Boise State University Bureau of Land Management: Idaho State Office Cover and title page photo generously donated by Michael Lanza, The Big Outside. The authors of this field guide would like to thank the following people for kindly offering their professional advice: Nancy Cole, Antonia Hedrick, Scott Koberg, Bill Moore, Nancy Shaw, Roger Rosentreter, and Brett VanPaepeghem. Thanks to following people who contributed outstanding plant photographs: Matt Fisk, Matt Lavin, Ian Robertson, and Clinton Shock. iii A Field Guide to Plants of the Boise Foothills Jamie Utz Michael Pellant Jessica Gardetto Edited by Corey Gucker First edition, 2013 iv Contents Introduction to the foothills ............. 6 - 9 How to use this field guide ….………..… 10 Key to symbols ……………...……………….… 11 Plant profiles …………....…………..… 12 - 159 Shrubs/Trees …….………….… 12 - 23 Forbs ……….………………….… 24 - 121 Grasses ……………………….. 122 - 159 Glossary …………………….………….. 160 - 162 References ……………….………...…. 163 - 164 Index ......................................... 165 - 169 by common name........... 165 - 167 by scientific name........... 168 - 169 5 Introduction to the Boise Foothills Location The foothills north of Boise, Garden City, and Eagle make a beautiful backdrop for the urban areas below. This ecosystem provides city residents unparalleled recreational opportunities, serves as important wildlife habitat, provides clean water to residents, and supports the local economy. The foothills are also home to a wide variety of plants that have important ecological and economic roles. Native plants have naturally evolved with and adapted to the local foothills climate and soils. Nonnative plants are species that were introduced (accidentally or purposefully) to the foothills ecosystem. Both types of plants are important to understanding and appreciating the foothills. This guide provides the user with a tool to identify some of the more common native and nonnative plants found in the lower portion of the Boise Foothills (Figure 1). 55 21 16 44 20 26 84 Figure 1. The blue line on the map above indicates a general boundary that was used to select the plants featured in this field guide. 6 Environment Vegetation in the foothills is a product of the soils, slope, aspect, elevation, and the local climate. Soils are important because their texture, depth, nutrients, and other characteristics govern the types of plants found in this ecosystem. Additionally, aspect (i.e. the direction the slope of a hill faces), elevation, and precipitation are all factors that influence the presence and proportions of foothills plants. Disturbances such as wildfires and off-road vehicle or off-trail use can negatively affect this environment by reducing native plants and encouraging the entry or increase of nonnative invasive plants. Native Plants Plants native to the foothills evolved to withstand hot and dry summers, cold winters, periodic droughts, and infrequent wildfires. A healthy native foothills plant community is dominated by big sagebrush and bitterbrush with a diverse understory of grasses, forbs (wildflowers), lichens, and mosses (Figure 2). Foothills plant communities also contain several rare native plants, which are sparsely distributed and adapted to unique habitats. Figure 2. A healthy foothills plant community is a diverse mixture of shrubs, forbs, and grasses. Healthy native plant communities are resilient to natural disturbances and provide good watershed protection and wildlife habitat. 7 Nonnative Plants Most of the nonnative plants found in the Boise Foothills are of European or Asian origin. Some nonnative plants have desirable characteristics and were purposefully planted to meet land management objectives. However, other undesirable nonnative invasive plants have spread accidentally into the foothills, causing ecological and economic damage. These invasive plants compete with native plants for space, water, and nutrients. Several invasive grasses, exemplified by cheatgrass (Figure 3), increase the frequency and size of wildfires in the foothills, threatening homes and intact native plant communities. The negative impacts of some invasive plants are so severe that they are assigned the classification of noxious weed. A noxious weed is designated by the state of Idaho as any plant having the potential to cause injury to public health, livestock, crops, or other land or property. Figure 3. This photo shows cheatgrass dominating the landscape after a 2009 wildfire at the Eagle Sports Complex. Dominance by this invasive annual grass has reduced the abundance of native plants and increased the potential for future wildfires. 8 Field Guide Contents This guide was developed to assist foothills users and residents to identify the more common native and nonnative plants in this area. It does not include all of the plant species found in the foothills, and it does not include plants growing along streams or in wetland areas. Foothills plants outside of the area shown in Figure 1 are not well represented in this guide. A digital version of the field guide is available on the Healthy Hills Initiative website, along with information on additional Boise Foothills plants, methods to control invasive plants, fire effects on plants, and methods to restore native plant communities (Figure 4). Scan the QR code below with your smartphone to access the Healthy Hills Initiative website. Figure 4. Restoring the Boise Foothills ecosystem is a worthwhile cause that has many benefits including increasing plant diversity, attracting a variety of wildlife species, enhancing recreational activities, and reducing the risk of wildfire. 9 How to use this field guide This field guide is designed to facilitate accurate identification of native and nonnative foothills plants. • Color-coded bars across the top of each page indicate plant life form: green for trees or shrubs, pink for forbs, and blue for grasses. • The typical life cycle of each plant is given at the top right of each page: annuals are plants that complete their life cycle in a single year, biennials are plants that require two years to complete their life cycle, and perennials are plants that live for more than two years. Some plants naturally have more than one life cycle classification, and some plant life cycle classifications can vary according to regional growing conditions. • Widely used common names of plants are listed at the top of each page, and alternative common names (if applicable) are listed in parentheses below. • Currently recognized scientific names (as of 2013) are listed beneath the common names; nomenclature follows the NRCS PLANTS database (USDA, NRCS 2013: • The description section includes plant characteristics most useful for identification. • The interesting facts section includes information about plant natural history, importance to wildlife, and cultural uses. This section may include information from regions beyond the plant’s Boise Foothills range. • Symbols at the bottom of each page allow for at-a-glimpse comprehension of certain plant features; the key on the following page lists these symbols and their meanings. • Color photos of each plant are provided; photos lacking credits are courtesy of the BLM. • Measurements of plant attributes are given in abbreviated English units (inches: in, feet: ft), except for extremely small measurements, which are given in millimeters (mm). • Definitions of botanical terms can be found in the glossary at the end of the field guide. • Selected references are listed at the end of the field guide. 10 Key to symbols The symbols below represent certain key plant characteristics. Native to Idaho Introduced to Idaho Important to wildlife Attracts pollinating insects Rare plant Considered moderately to highly flammable A nonnative plant designated by the state of Idaho as a noxious weed that is injurious to public health, agriculture, recreation, wildlife, or property 11 SHRUB Antelope bitterbrush Purshia tridentata Description • Height of mature plants is 5 to 8 ft, and width is typically 4 to 6 ft • Trunk is thick and extensively branched • Leaves are bright to olive green and wedge-shaped with 3 terminal lobes • Leaf surfaces are hairless and smooth, while leaf undersides are covered in soft white hairs • Flowers are small, bright yellow, fragrant, and appear singly in the leaf axils in late spring Interesting facts Antelope bitterbrush is common in the Boise Foothills. It is a relatively long-lived shrub; in California, 128 year-old plants have been reported. Antelope bitterbrush sometimes resprouts after fire, but in areas with frequent fires, other fire-tolerant plants or weeds may replace it. Many herbivores native to the foothills rely on this shrub as a critical food source, especially during harsh winters. Native Americans used antelope bitterbrush in poultices for rashes, in teas to treat colds or pneumonia, and as a laxative. Seeds have a very bitter flavor, hence the name ‘bitterbrush’. 12 PERENNIAL Top and middle photos courtesy of M. Lavin 13 SHRUB Basin big sagebrush Artemisia tridentata subsp. tridentata Description • Height is 3 to 5 ft on average, but may reach 10 ft on deep soil sites; shape is rounded to spreading irregular • Main trunk is short and divides into several longer branches that tend to grow up rather than out; bark is stringy • Leaves are pale green to gray-blue, 0.75 to 1.25 in long, coated with fine silver hairs, and have 3 lobes at the tips • Flowers are small, dark yellow, and appear on upright, uneven stems above the leafy crown • Flowers appear in September Interesting facts Basin big sagebrush is the most common sagebrush in the lower Boise Foothills, whereas a similar subspecies called Wyoming big sagebrush (A. t. subsp. wyomingensis) is found in the southern plains surrounding Boise. Like many sagebrush species, basin big sagebrush produces two types of leaves: deciduous leaves that are produced each spring and are shed in the fall, and persistent leaves that remain on the shrub throughout the year. Deciduous leaves have long bases and bell-shaped lobes, while persistent leaves have short bases and three-lobed tips. Essential oil glands in the leaves give many sagebrush plants (Artemisia spp.) a fragrant, turpentine-like smell. This feature may reduce its palatability to some herbivores; however, sagebrush-dependent wildlife like pygmy rabbits and Greater Sage-grouse often depend on it as a staple food source. 14 PERENNIAL Photos courtesy of M. Lavin 15 SHRUB Foothills sagebrush (Xeric big sagebrush) Artemisia tridentata subsp. xericensis Description • Height of mature plants usually exceeds 3 ft • Branches typically radiate from a single trunk in a classic tree shape; bark is stringy and ranges from brown to gray-green in color • Persistent leaves are short, wedge-shaped, and widest just beneath the 3-lobed tips; deciduous leaves are 0.75 to 1 in long with leaf margins that curve outward (For a discussion on the two types of leaves produced by big sagebrush species, see basin big sagebrush) • Flowers are small, dark yellow, and appear in September; flowering stems are produced on most branches and appear unevenly above the crown Interesting facts This subspecies is a naturally occurring hybrid between basin big sagebrush and mountain big sagebrush. Like all subspecies of big sagebrush, foothills sagebrush provides food and cover for mammals and birds including pronghorn and Greater Sage-grouse. Some species of sagebrush are fluorescent when submerged in water or alcohol and exposed to a black light, a method sometimes used to distinguish between species and subspecies. Foothills sagebrush glows a creamy blue color during this test, while basin big sagebrush does not glow at all. 16 PERENNIAL 17 SHRUB Gray rabbitbrush (Rubber rabbitbrush) Ericameria nauseosa Description • Height ranges from 2 to 7 ft, and width ranges from 1 to 4 ft • Leaves and fine stems are dusty green to gray due to the presence of white to gray hairs • Leaves are narrow, linear, and measure 1 to 3 in long; leaves grow straight without twisting • Flowers are dark yellow, densely-packed, and bloom in late summer or early fall Interesting facts Small mammals and birds utilize gray rabbitbrush as a food source and as habitat. Native Americans used gray rabbitbrush to treat coughs and colds. Topical application of the plant eased itching, and chewing on the plant reduced thirst. Stems and leaves of gray rabbitbrush produce a sticky latex gum that can be used to create a high quality rubber. This feature drew the interest of scientists during the rubber shortages of World War II, but rubber from gray rabbitbrush could not be produced economically. Due to its high flammability, gray rabbitbrush may need special management in the wildland/urban interface. 18 PERENNIAL 19 SHRUB Green rabbitbrush (Yellow rabbitbrush, Douglas rabbitbrush) Chrysothamnus viscidiflorus Description • Height reaches up to 3 ft, and width is typically 1 to 2 ft • Stems branch near ground level and give the shrub a rounded or domed shape • Leaves are 0.5 to 2 in long, linear, and light to dark green with a distinctive lengthwise twist • Flowers are bright yellow, occur in flat-topped clusters, and appear in late summer Interesting facts Green rabbitbrush is a relatively short-lived shrub that vigorously resprouts after fire. Green rabbitbrush has a pungent smell and sticky texture, which explains the Latin species name viscidiflorus, meaning “sticky flower”. As the common name suggests, green rabbitbrush is highly palatable to rabbits. Native Americans utilized green rabbitbrush to treat skin ailments, colds, coughs, and in the making of orange and yellow dyes. Due to its high flammability, green rabbitbrush may need special management in the wildland/urban interface. 20 PERENNIAL Photos courtesy of M. Lavin 21 TREE Netleaf hackberry (Western hackberry, bastard elm) Celtis laevigata var. reticulata Description • Mature plant height ranges from 10 to 30 ft, and width ranges from 5 to 10 ft; may look more like a large shrub than a small tree when immature • Trunk is short and crooked with gray or reddish brown, warty bark • Limbs are numerous and scraggly but strong • Leaves are dense, emerge in late spring, and can have slightly toothed margins; undersides have distinct, netlike venation • Berries are reddish-orange, sweet, and edible; berries appear in the fall and contain a hard, cream-colored seed Interesting facts Netleaf hackberry is slow growing and long-lived. Trees may live 200 years or more. Netleaf hackberry attracts many wildlife species because it is often the only foothills tree capable of growing in very dry sites. Netleaf hackberry fruits are consumed in large quantities by small mammals and birds, and the strong branches make for popular perch or roost sites for even the heaviest predatory birds, like the great horned owl. Early homesteaders used netleaf hackberry wood in the construction of shelters and furniture. 22 PERENNIAL Bottom photo courtesy of M. Lavin 23 FORB Aase’s onion (South Idaho onion) Allium aaseae Description • Height may reach 2 in when plants are in flower • Flowering stems are smooth, green, leafless, and white at the base • Leaves are grass-like, about twice the length of nonflowering stems, and often found lying on the ground • Flowers occur close to the ground and are clustered in dome- or sphere-like inflorescences • Flowers have 6 pink to purple petals with deep pointed lobes; petals fuse and form a visible tube, which surrounds the pistils and stamens • Flowers appear in March or April Interesting facts Aase’s onion is a rare species, found only in southwestern Idaho. It prefers low-elevation sites with deep, sandy soils. In 2006, several Aase’s onion plants were salvaged from Ada County lands that were going to be developed as part of a landfill expansion. The “rescued” specimens were replanted and can be observed growing at the Idaho Botanical Garden. Aase’s onion looks very much like dwarf onion (A. simillimum) and was only recently recognized as genetically distinct. 24 PERENNIAL 25 FORB Annual sunflower (Common sunflower) Helianthus annuus Description • Height ranges from 1 to 6 ft • Leaves are broad, roughly heart-shaped, and covered with bristles; leaf margins are toothed • Stems are coated with stiff bristles and range from unbranched to highly branched • Flowers have long, narrow, yellow petals that surround a dull reddish-brown center, which resembles a pin cushion • Blooming occurs from July to September Interesting facts Annual sunflowers commonly grow along roads and in other disturbed areas. Seed-eating birds, especially mourning doves, tend to congregate in areas with sunflowers during the fall. The majority of sunflowers (Helianthus spp.) are the product of centuries of domestication and selection by Native Americans. The Paiute used a root extraction from annual sunflowers to alleviate rheumatism. Other tribes used various plant parts as an appetite stimulant, to make dyes, and as a source of fiber for rope, paper, and fabric. Sunflower seeds were also ground into a flour to make bread or cakes that could be stored for later use. 26 ANNUAL Photos courtesy of M. Lavin 27 FORB Arrowleaf balsamroot Balsamorhiza sagittata Description • Height ranges from 1 to 2 ft, and width is generally about 18 in • Leaves are large, dusty green, arrowhead-shaped, and emerge in the spring • Leaves and stems are both covered with silvery soft hairs • Flowers are large and sunflower-like with bright yellow petals surrounding a textured, darker golden center • Flowering occurs from April to May Interesting facts Arrowleaf balsamroot produces very large taproots. Postfire sprouting is common, and fire tolerance is considered high. Arrowleaf balsamroot is a high-protein, highly palatable forage that is important to deer and elk, especially in winter and spring. Seeds are eaten by birds and small mammals. Many Native American tribes used arrowleaf balsamroot as a food and medicine. Young stalks, roots, and seeds were eaten raw or cooked. Recent research has established that arrowleaf balsamroot contains antibacterial compounds. 28 PERENNIAL Photos courtesy of M. Lavin 29 FORB Bachelor’s button (Garden cornflower) Centaurea cyanus Description • Height may reach 3 ft • Leaves are generally gray-green, several inches long, and linear with smooth margins; edges of the basal leaves may be toothed or lobed • Stems are slightly hairy and arise from the base of the plant • Flower heads are 1 to 2 in wide with showy, trumpetlike, white to purple petals with 3 deep lobes at the tips • Flowering occurs from summer through fall Interesting facts Bachelor’s button is native to the Mediterranean region of Europe but has been cultivated as an ornamental plant for hundreds of years in much of North America. It has escaped cultivation and can now be found on disturbed soils in the foothills. Birds, butterflies, moths, and bees are attracted to bachelor’s button. Young shoots and flowers are edible and have been used to flavor teas. Early European medicinal uses included the treatment of conjunctivitis, constipation, ulcers, and bleeding gums. 30 ANNUAL Top photo courtesy of Jean Pawek 31 FORB Ballhead gilia Ipomopsis congesta subsp. congesta Description • Growth form is variable in the Boise Foothills, ranging from a low-growing mat only a few inches tall to an erect form up to 2 ft tall • Leaves are small, linear, may have soft silvery hairs, and generally decrease in size from the base to the top of the plant • Individual white to pink flowers are crowded into a ballshaped inflorescence at the tips of unbranched stems • Flowers have 5 separate flared petals; blooms appear in early or midsummer Interesting facts Ballhead gilia often occupies disturbed, sandy soils in the Boise Foothills. The Ipomopsis genus name is derived from the Greek words ipo meaning “to strike” and opsis meaning “appearance”, which indicates the plant’s striking appearance. The species name congesta is Latin for ”crowded” or “closely arranged”, which aptly describes ballhead gilia flower heads. 32 PERENNIAL Photos courtesy of M. Lavin 33 FORB Bastard toadflax Comandra umbellata Description • Height ranges from 2 to 12 in • Leaves are numerous and linear with pointed tips and bases that clasp the stems; leaves are rarely longer than 1.5 in • Leaves are thick and sometimes bluish with a somewhat rough texture • Leaves have a prominent central vein but no other obvious venation • Flowers are small, star-shaped, and occur in clusters at the top 6 to 10 in of main stems; flower petal color ranges from white to green, pink, or pale purple • Flowering occurs in spring or summer Interesting facts Bastard toadflax can spread by prolific root growth. Roots can also rob the nutrients of neighboring plants. Small, oily fruits produced by bastard toadflax are likely eaten by birds and small mammals. The roots of bastard toadflax stain blue when cut, a feature exploited by Native Americans to make blue dyes. Extracts from leaves were used to treat lung pains and labored breathing associated with colds and other respiratory ailments. The sap of bastard toadflax was used externally to treat skin cuts and sores. 34 PERENNIAL Photos courtesy of M. Lavin 35 FORB Blue Mountain buckwheat Eriogonum strictum Description • Height may reach 2 ft when in flower but is typically much shorter when not in flower; often found as a lowgrowing mat up to 15 in wide • Leaves are all basal, small, woolly, and paddle- to spade-shaped • Flowers grow in tight, terminal, globular clusters that range from white or pale yellow to orange or rose • Stamens often extend beyond the flowers • Flowers appear in the summer months Interesting facts This species is slow growing, long-lived, and common in rocky soils and habitats. The palatability of Blue Mountain buckwheat is thought to be low for most herbivores. This plant and other closely related species are an important source of nectar for Bauer’s dotted-blue butterfly, an extremely rare species in the Intermountain West. 36 PERENNIAL Photos courtesy of M. Fisk 37 FORB Bur buttercup (Curveseed butterwort) Ceratocephala testiculata Description • Height is typically 2 to 4 in; plants often occur in dense mats and can cover a large area • Leaves are gray-green, very small, thick, and covered with fine hairs; leaf tips are forked in a way that resembles a bird’s foot • Flowers are produced on leafless stems; flowers measure less than 0.25 in across and have 5 bright to dull yellow petals • Flowers develop into many horned seed heads that form a spiky bur-like unit that becomes dry and hard • Blooming occurs in early- or mid-spring, and seed heads appear in late spring Interesting facts Bur buttercup is one of the first plants to produce seeds in the foothills. Tough burs formed at the end of the bur buttercup life cycle are easily attached to and transported by fur or clothing. Burs contain 5 to 80 seeds. Bur buttercup contains a toxic compound, which can cause serious health problems for livestock. Sap from green plants can irritate the skin. 38 ANNUAL Bottom photo courtesy of M. Fisk 39 FORB Desert madwort (Yellow alyssum) Alyssum desertorum Description • Height ranges from 3 to 10 in; growth forms can range from prostrate to erect as the plant matures • Stems are simple, range from few to many, and arise from the base; leaves and stems are pale green or grayish due to a layer of silvery hairs • Leaves are small, linear, generally less than 1 in long, and taper to a point where they attach to the stem • Flowers are pale yellow and appear along the upper 4 in of stems; flower stalks typically produce 30 to 40 flowers, which are less than 0.1 in across • Flowers first bloom at the bottom of the stalk and last at the top; flowering occurs in late spring to early summer • Seed pods are very small, flattened, and shaped like table tennis paddles Interesting facts When magnified, the fine hairs present on the stems and leaves of desert madwort appear star-shaped. This distinctive botanical characteristic is referred to as a stellate hair pattern in many plant identification keys. 40 ANNUAL Photos courtesy of M. Fisk 41 FORB False yarrow (Douglas’ dustymaiden) Chaenactis douglasii Description • Height of mature plants ranges from 8 to 24 in • Stems are simple and arise from the base; flowering stems and leaves are covered with cobwebby hairs, but hairiness may decrease as plants mature • Leaves are often sparse and found primarily low on the stems; leaves are gray-green and highly dissected, appearing lacy or fern-like • Flowers are typically white to pale pink and tubular with forked styles that extend beyond the curled petals • Flowers occur in groups of 2 to more than 25 in crowded flat- to round-topped inflorescences at the ends of stems • Blooming occurs from May to June Interesting facts False yarrow pollen and nectar are attractive to numerous pollinators and other insects. The insects associated with this species are important to Greater Sage-grouse chicks. False yarrow is also utilized by other birds and small mammals. Native Americans used false yarrow to treat chapped hands, insect bites, boils, and swellings. 42 BIENNIAL/PERENNIAL Photos courtesy of M. Lavin 43 FORB Fiddleneck (Devil’s lettuce, bristly fiddleneck) Amsinckia tessellata Description • Height ranges from 6 to 24 in • Stems are weak, erect, and branch infrequently • Leaves are narrow and elongate, measuring up to 5 in long and 0.4 in wide • Basal leaves are numerous and crowded, while stem leaves become sparser and smaller near the top of the plant; ends of leaves can appear crimped or coiled • Leaves and stems are heavily covered with dense, stiff, long bristles • Flowers line the flowering stalks and uncoil upward as blooming occurs from the bottom to the top of stems; the coiled end of a flowering stem resembles the neck of a fiddle • Flowers are yellow or orange and have 5 petals; blooms appear in late spring Interesting facts Fiddleneck is common on dry, sandy, disturbed sites. Seeds produced by fiddleneck are spiny and easily attach to fur and clothing, suggesting that animals as well as humans can promote long-distance seed dispersal. The distinctive bristles covering fiddleneck plants can cause skin irritations. 44 ANNUAL Bottom photos courtesy of M. Lavin 45 FORB Gairdner’s beardtongue (Rock penstemon) Penstemon gairdneri Description • Height ranges from 12 to 24 in • Stems are numerous, sometimes reddish, and emerge from a somewhat woody base • Leaves are narrow, elongate, coated with fine hairs, and present in large numbers all along the stems • Leaves near the top of the plant are pointed, while those near the base are more rounded • Flowers are 5-lobed, lavender to pink, and tubular; flower petals flare to form a flat face, and floral tubes are typically 0.5 to 0.75 in long and whitish on the inside • Flowers may have sparse short, sticky hairs; flowering occurs in late spring Interesting facts Although penstemons (Penstemon spp.) are not commonly grazed by mammalian wildlife species, their showy flowers do attract many bees, hummingbirds, and moths. 46 PERENNIAL 47 FORB Gray’s biscuitroot (Gray’s desert parsley) Lomatium grayi Description • Height may reach 2 ft • Leaves are highly dissected and fern-like and have a pungent smell when rubbed or crushed • Flowering stems are leafless and have many groups of tightly clustered, small, bright yellow flowers that radiate out from a single point • Blooming occurs in April or May; flowers may fade to white after the peak flowering period Interesting facts In early spring, Gray’s biscuitroot is among the first plants to green up and flower, making it important to early spring pollinators including some rare butterflies. Gray’s biscuitroot is valuable in Greater Sage-grouse habitat because it attracts insects, which are important to chick development. The Paiute readily ate young Gray’s biscuitroot stems, but the taproot was considered a starvation food and only eaten when other tastier foods were scarce. 48 PERENNIAL Photos courtesy of M. Fisk 49 FORB Hoary tansyaster (Purple aster) Machaeranthera canescens Description • Height is generally 12 to 30 in • Stems are spreading to erect, highly branched, and have a covering of dense, sticky hairs • Leaves are narrow, linear, and up to 2 in long; leaves may have minutely or finely toothed edges • Flower heads are daisy-like with yellow centers surrounded by pale to dark purple petals • A green structure occurs beneath and clasps the flower head; it has short modified leaves that curl outward • Flowering occurs in late summer or early fall Interesting facts Hoary tansyaster often appears soon after fire or other soil disturbances. Numerous pollinators and other insects are attracted to this forb. Hoary tansyaster attracts insects that are important in the diets of Greater Sage-grouse chicks. Some Native American groups used hoary tansyaster to treat nose and throat problems. 50 PERENNIAL 51 FORB Hood’s phlox (Showy phlox) Phlox hoodii Description • Height is generally less than 4 in, but width can be 12 in; often found growing as a dense mat or mound • Stems are stiff, somewhat woody, covered by tiny, ridged, linear leaves, and branch from the base • Leaves typically have sharp points and rarely measure longer than 0.5 in; basal leaves are covered by cobwebby hairs • Flowers are commonly white to purple or blue; 5-lobed, flared petals fuse into a floral tube that is about 10 mm long • Flowering occurs in early spring before most other foothills wildflowers Interesting facts Hood’s phlox grows in a dense mat, whereas longleaf phlox (page 58) often grows more upright. Leaves at the base of Hood’s phlox are usually quite hairy, while longleaf phlox leaves have few or no hairs. Aboveground portions of the plant emerge from a coarse woody taproot, which may extend several feet deep. Hood’s phlox resprouts from this taproot soon after fire. The Blackfoot people used Hood’s phlox as a mild laxative for children, to alleviate chest pains, and to make a yellow dye. 52 PERENNIAL Photos courtesy of M. Lavin 53 FORB Jim Hill mustard (Tall tumblemustard) Sisymbrium altissimum Description • Height of mature plants ranges from 2 to 5 ft; immature plants lack erect stems and exist only as a leafy rosette in late winter or very early spring • Stems are highly branched at the top third of the plant, giving this plant a bushy appearance • Basal leaves are highly dissected, can reach 8 in long and 3 in wide, and look like narrow dandelion leaves; upper leaves are deeply dissected into very fine, thin, linear lobes • Flowers have 4 pale yellow petals; stamens and styles often extend beyond the petals • Flowering occurs in late spring and early summer; seed pods are conspicuous, linear, and measure up to 5 in long Interesting facts Dried plants are easily blown by the wind, and seeds are dispersed as it tumbles. A single seed pod can contain 120 seeds. This species was thought to have spread across the

also available

National Parks