This description provides characteristics that may be relevant to fire ecology, and is not meant for identification. Keys for identification are available [11,38,46,47,50,59,60,80].
Broadleaf lupine is a native perennial forb. It has a bushy, densely branched growth habit originating from a woody caudex and an extensive root system [39]. Plant heights range from 1 to 4 feet (0.3-1.2 m) on erect stems that are subglabrous to minutely strigose [59,60,80]. The leaves are palmately compound with 5 to 10 leaflets. The leaflets are elliptic to lance-shaped, 1 to 3 inches (2.5-7.6 cm) long, glabrous above, and minutely strigose beneath. The inflorescence is a showy raceme from 4 to12 inches (10-30 cm) long with numerous whorled or scattered pea-like flowers. The fruit is a legume that is 0.8 to 1.8 inches (2-4.5 cm) long and densely hairy. The legume pod contains 6 to 10 dark brown seeds [11,38,45,53,59,80].
Physiology: Broadleaf lupine is a nitrogen-fixing legume [17,61]. Seventeen years after thinning on a coast Douglas-fir site, broadleaf lupine was 1 of 2 species that accounted for only 1% of understory biomass, yet contributed 1/3rd of the nitrogen annually cycled [57].
In the United States, broadleaf lupine distribution extends from Washington south to California and east to Utah, Nevada, and New Mexico. In Canada, it is only found in British Columbia. Plants Database provides a distributional map of broadleaf lupine.
Varieties: Lupinus latifolius var. latifolius occurs from British Columbia south to California [45,47,60]. Lupinus latifolius var. barbatus, L. l. var. dudleyi, L. l. var. parishii, and L. l. var. viridifolius occur in California [45]. Lupinus latifolius var. columbianus is found throughout the Intermountain West [11,45,80].
Fire adaptations: Broadleaf lupine has a deep, lateral root system and is capable of spreading vegetatively from root sprouts [3]. It is likely that these characteristics provide for regeneration following fire. Depending on the severity of top-kill by fire, sprouting from the caudex would also be a possibility. Information is lacking on the regeneration of broadleaf lupine seed after fire. Further research is needed in this area.
FIRE REGIMES for the mesic communities where broadleaf lupine occurs most often are mostly mixed- to high-severity with fire return intervals ranging from 35 to 200 years. In some cases, fire return intervals may be >200 years [19].
The following table provides fire return intervals for plant communities and ecosystems where broadleaf lupine is important. Find fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find FIRE REGIMES".
Community or Ecosystem Dominant Species Fire Return Interval Range (years) silver fir-Douglas-fir Abies amabilis-Pseudotsuga menziesii var. menziesii >200 grand fir Abies grandis 35-200 [7] tamarack Larix laricina 35-200 [63] western larch Larix occidentalis 25-350 [8,13,26] Engelmann spruce-subalpine fir Picea engelmannii-Abies lasiocarpa 35 to >200 [7] whitebark pine* Pinus albicaulis 50-200 [1,5] Rocky Mountain lodgepole pine* Pinus contorta var. latifolia 25-340 [12,13,76] Sierra lodgepole pine* Pinus contorta var. murrayana 35-200 western white pine* Pinus monticola 50-200 [7] quaking aspen (west of the Great Plains) Populus tremuloides 7-120 [7,34,56] mountain grasslands Pseudoroegneria spicata 3-40 (x=10) [6,7] Rocky Mountain Douglas-fir* Pseudotsuga menziesii var. glauca 25-100 [7,9,10] coastal Douglas-fir* Pseudotsuga menziesii var. menziesii 40-240 [7,58,67] California mixed evergreen Pseudotsuga menziesii var. menziesii-Lithocarpus densiflorus-Arbutus menziesii <35 [7] California oakwoods Quercus spp. <35 Oregon white oak Quercus garryana <35 western redcedar-western hemlock Thuja plicata-Tsuga heterophylla >200 western hemlock-Sitka spruce Tsuga heterophylla-Picea sitchensis >200 mountain hemlock* Tsuga mertensiana 35 to >200 [7] *fire return interval varies widely; trends in variation are noted in the species reviewThe following table describes site characteristics for broadleaf lupine throughout its distribution.
Soils: Broadleaf lupine can persist in low-fertility soils because of its ability to fix nitrogen [40]. It may increase soil fertility. On sites in the Olympic Mountains, the soils directly surrounding the nitrogen-fixing broadleaf lupine plants had twice the nitrogen, more organic matter, and more phosphorus than adjacent soils [15].
The 1980 eruption of Mount St. Helens provided a unique opportunity to study the growth response of broadleaf lupine on the newly deposited volcanic substrates. A greenhouse study on 4 soil samples taken from the site during the summers of 1980 and 1981 revealed that broadleaf lupine exhibited the greatest growth response on tephra and the least growth on the pyroclastics (volcanic rock fragments). Subsequent soil samples collected from 1982 and 1983 revealed a large growth response on 3 substrates (pyroclastics, mud, and tephra) [27].
The soil descriptions for 2 plant communities where broadleaf lupine is dominant follow.
Olympic National Forest, subalpine fir/broadleaf lupine association: Soils are shallow, coarse-textured, and very rocky. They have high permeability and low water holding capacity. Soils are cold in winter and warm in summer; the mean soil temperature for August is 54 °F (12 °C). The soil temperature regime is frigid, and the soil moisture regime is xeric. Stands in this type have burned frequently in the past, which may have contributed to the apparently low fertility of these sites. Other associations in which broadleaf lupine was a minor component have shallow, rocky soils [43].
Mount Rainier National Park, green fescue meadows: Soils are relatively dry, well-drained loams that are primarily derived from geologically young deposits of glacial till and volcanic ash [73].
Hall [36] states that broadleaf lupine seeds are poisonous to animals because of the alkaloids they contain. Further research is needed on this topic [55]. The teratogenic alkaloid anagyrine has been found in broadleaf lupine and can cause "crooked calf disease" if a pregnant cow consumes the flowers or seed pods between the 40th and 70th days of gestation [65].
The importance of broadleaf lupine to Columbian black-tailed deer is relatively low [23].
Palatability/nutritional value: Columbian black-tailed deer on Vancouver Island, British Columbia, eat broadleaf lupine leaves casually or when under stress [23]. Birds eat the seeds [51].
Cover value: No information is available on this topic.
In addition to the plant communities listed above, broadleaf lupine is known to
occur in a variety of other communities. Communities where broadleaf lupine is
dominant include:
Mount Rainier National Park, Washington
broadleaf lupine/American bistort (Polygonum bistortoides)
Sitka valerian (Valeriana sitchensis)/broadleaf lupine
greenleaf fescue (Festuca viridula)/broadleaf lupine
pink mountainheath (Phyllodoce empetriformis)/broadleaf lupine [32,44]
Eastern Washington national forests
broadleaf lupine [51]
Gifford Pinchot National Forest, Washington
coast Douglas-fir/vine maple/western fescue
(Pseudotsuga menziesii var. menziesii/Acer circinatum/Festuca occidentalis) [78].
Blue Mountains, eastern Oregon and southeastern Washington
poke knotweed (Polygonum phytolaccifolium) [35]
Broadleaf lupine is a component of the vegetation in the following communities:
California
quaking aspen (Populus tremuloides) riparian forest [48]
giant sequoia (Sequoiadendron giganteum) [42,71]
Eastern Washington national forests
timber oatgrass (Danthonia intermedia)
black alpine sedge (Carex nigrans)
saw-leaved sedge (Carex scopulorum var. prionophylla)
subalpine fir/cascade azalea (Rhododendron albiflorum)/arrowleaf ragwort (Senecio triangularis)
subalpine fir/false bugbane (Trautvettaria caroliniensis)
subalpine fir/globeflower (Trollius laxus)
subalpine fir/mountain arnica (Arnica latifolia)-skunkleaf
polemonium (Polemonium pulcherrimum)
subalpine fir/Labrador tea (Ledum glandulosum)-grouse
huckleberry (Vaccinium scoparium)
subalpine fir/twinflower (Linnaea borealis var. longiflora) [51]
Crater Lake National Park, Oregon
gray alder/blue wildrye (Alnus incana/Elymus glaucus) [54]
Pacific Northwest
western moss heather (Cassiope mertensiana)-pink mountainheath
Sitka valerian-green false hellebore (Veratrum viride)
showy sedge (Carex spectabilis)
American saw-wort (Saussurea americana)
purple monkeyflower (Mimulus lewisii) [31,32]
Broadleaf lupine regenerates by seed and vegetative means. The deep, lateral root system can spread vegetatively from root sprouts [3]. Broadleaf lupine regenerated from root fragments that had been transported by the debris avalanche during the eruption of Mount St. Helens [24,25,77]. Vegetative growth also emanates from the perennating buds on the woody caudex [4].
Pollination: Broadleaf lupine is insect pollinated [29]. Bees pollinate broadleaf lupine on the Olympic National Forest, Washington [53].
Breeding system: There is considerable genetic variation within local populations of broadleaf lupine. Both diploid and tetraploid forms occur in some populations [29].
Seed production: Six to ten large seeds are produced per seed pod [39,45]. One terminal cluster can produce as many as 35 pods [80].
Seed dispersal: The pod splits at maturity, releasing several seeds [53]. The seeds are large and are not dispersed widely [81]. Dispersal is mainly by gravity and water. Seedlings generally establish within a few meters of the parent plant [24].
Seed banking: Some Lupinus species form a seed bank [37], but information is lacking for broadleaf lupine. Further research is needed in this area.
Germination: The optimal temperature for the germination of broadleaf lupine seeds in alpine tundra is 68 °F (20 °C) [14]. The greatest percentage (~40%) of germination of broadleaf lupine seeds in a greenhouse environment occurred about 168 hours after imbibition [39].
Seedling establishment/growth: Seedlings have pronounced taproots, but lateral root development is limited, and only small rosettes of leaves are initially formed [3].
Asexual regeneration: Broadleaf lupine reproduces from root sprouts, root fragments, and from the caudex [3,4,24,25,77].
After the 1980 eruption of Mount St. Helens, studies were done on the plants that had tephra (coarse, airborne material) deposited on top of them. Broadleaf lupine's perennating buds remained on the woody caudex at the soil surface, but the stems easily penetrated up through the deposit. Subsequent seed production was substantial, and broadleaf lupine seedlings established in the tephra [4].
Broadleaf lupine was a common colonizing species on many of the primary successional habitats after the eruption of Mount St. Helens [18,21,28,40,77]. On debris avalanche sites at Mount St. Helens, broadleaf lupine altered local soil moisture conditions by shading, and altered soil nutrient status by nitrogen fixation [24].
There was an abundance of broadleaf lupine on a pioneer community dominated by red alder (Alnus rubra) and Sitka willow (Salix sitchensis) on Bald Mountain, Vancouver Island, British Columbia [23]. In Mount Rainier National Park, Washington, broadleaf lupine is associated with young and developing communities but is most characteristic of the "best developed" and "most mature" meadow communities [44]. Broadleaf lupine is a dominant species in both early seral and old-growth stands of Olympic National Forest [43].
The rapid development of an extensive lateral root system should allow broadleaf lupine to exploit resources effectively and thus succeed in competing for water, light, and space later in succession. The presence of broadleaf lupine plants in canopy gaps of old-growth forests of coast Douglas-fir, mountain hemlock (Tsuga mertensiana), and western redcedar (Thuja plicata) confirms its ability to succeed in a strongly competitive environment [3].
Broadleaf lupine is a valuable tool for rehabilitation of disturbed sites because it grows well on droughty and low-fertility sites, colonizes disturbed areas, has a deep root system for stabilizing soil, and forms associations with nitrogen-fixing bacteria [29]. It is commonly used for erosion control [29,38].
Broadleaf lupine seedlings grown in a greenhouse were used for rehabilitation of Paradise Meadow in Mount Rainier National Park. The survival rate for all forbs planted in the revegetation plots averaged 94%. Broadleaf lupine and other forb species spread faster than sedges (Carex spp.). Seeding with broadleaf lupine seeds was successful on these plots [68]. Survival of outplanted broadleaf lupine seedlings, also grown in the greenhouse, was successful after 2 years on a native plant garden (Biscuit scabland restoration) in the Columbia River Gorge, Oregon [82,83].
Lupinus latifolius is a species of lupine known by the common name broadleaf lupine. It is native to western North America from British Columbia to Baja California to New Mexico, where it is common and can be found in several types of habitat. There are several subtaxa, described as subspecies or varieties, some common and some rare. They vary in morphology. In general this plant is an erect perennial herb. It grows 30 centimeters to over two meters in height, in texture hairy to nearly hairless. Each palmate leaf is made up of several leaflets, those on larger plants up to 10 centimeters long. The inflorescence bears many flowers, sometimes in whorls. Each flower is one to two centimeters in length, purple to blue to white in color, the spot on its banner yellowish, pinkish, or white.
One rare subtaxon, Lupinus latifolius var. barbatus, is endemic to the Modoc Plateau of northeastern California and adjacent territory in Oregon and Nevada. The subtaxon dudleyi is known only from the San Francisco Bay Area.
It is a larval host to Boisduval's blue, clouded sulphur, orange sulphur, Persius duskywing, and silvery blue butterflies.[1]
Lupinus latifolius plants in alpine meadow Lupinus latifolius is a species of lupine known by the common name broadleaf lupine. It is native to western North America from British Columbia to Baja California to New Mexico, where it is common and can be found in several types of habitat. There are several subtaxa, described as subspecies or varieties, some common and some rare. They vary in morphology. In general this plant is an erect perennial herb. It grows 30 centimeters to over two meters in height, in texture hairy to nearly hairless. Each palmate leaf is made up of several leaflets, those on larger plants up to 10 centimeters long. The inflorescence bears many flowers, sometimes in whorls. Each flower is one to two centimeters in length, purple to blue to white in color, the spot on its banner yellowish, pinkish, or white.
One rare subtaxon, Lupinus latifolius var. barbatus, is endemic to the Modoc Plateau of northeastern California and adjacent territory in Oregon and Nevada. The subtaxon dudleyi is known only from the San Francisco Bay Area.
It is a larval host to Boisduval's blue, clouded sulphur, orange sulphur, Persius duskywing, and silvery blue butterflies.
