Kingdom: Plantae

Phylum: Magnoliophyta -- flowering plants

Class: Magnoliopsida -- dicotyledons

Family: Polemoniaceae -- phlox

Common Name: Scarlet gilia, skyrocket

Species Code: GIAG, IPAGA3

Origin: Native to dry open areas from shrub-steppe to open dry forests from British Columbia to northern California east to Montana and New Mexico.

Rare: no

Form: forb, biennial or short-lived perennial from a taproot; 20-100 cm tall, with 1 to several stems, slightly pubescent and stipitate-glandular at least above.

Duration: biennial

Longevity: short

Habitat Type: prairie

Wetland Indicator Status: not listed

Leaves: less than 10 cm long, pinnatifid or bipinnatifid into 9 to 11 linear lobes; basal leaves forming a rosette, withering by anthesis; cauline leaves alternate, reduced above, 5-7 lobed, puberulent to glabrous.

Mature height: 12-28 inches

Flowers: numerous in a thyrsoid to paniculiform inflorescence; calyx glandular puberulent, 4-11 mm long, campanulate; corolla red flecked with white (or occasionally white or white flecked with red), with a long flaring tube 15-30 mm long, lobes spreading, acute to attenuate, ovate to lanceolate, stamens and style exserted.

Flower color: red, white

Bloom: June, July, August, September

Bloom starts on: mid May

Bloom ends on: early September

Fruit: capsule, 4-9 mm long, ellipsoid; seeds about 2 mm long, elliptic, flattened, mucilaginous when wet.

Characteristics:
Ipomopsis aggregata (Pursh) V. Grant ssp. aggregata is the currently accepted name.
Usually considered a biennial, but may persist as a rosette for several years before flowering and is probably more properly considered a monocarpic perennial.
362,416 seeds/lb (USDA NRCS Pullman PMC 2009).
Seed size varies widely both within a population and on an individual plant. Size is inversely related to the number of seeds set per capsule and the number of seeds set is positively related to pollinator effectiveness (Wolf et al 1986).
n=7.
Pollinated by hummingbirds (Price & Waser 1982, Waser & Price 1982, Waser 1978, Kohn & Waser 1985, Campbell et al 1991) and hawk moths (Elam & Linhart 1988). Queen bumblebees, swallowtail butterflies, and hawk moths are rare pollinators (Campbell et al 1991). In Colorado the long-tongued Bombus appositus is a more effective pollinator than hummingbirds when the bumblebee occurs in sufficient numbers. Syrphid flies also visit the flowers (Mayfield et al 2001).
Flowers are perfect.
Polyploids are not known.
Native peoples had medicinal uses (Parish et al 1996).
Fruit is a capsule.
Self-incompatible (Wolf et al 1986, de Jong et al 1992, Mayfield et al 2001).
Xenogamous (Elam & Linhart 1988). Self-pollinated ovules are aborted (Waser & Price 1991). Protandrous (Campbell et al 1991, Mayfield et al 2001).
Seeds are expelled explosively.
Said to be poisonous but sheep apparently eat it (St. John 1963).

Sun requirement: full sun

Soil moisture: xeric

Precipitation: 10-15 inches (USDA NRCS PLANTS Database 2009).

Sowing time: fall

Transplant time: spring or fall

Stratification: cold moist

Seed yield: low

Seed harvest: difficult

Seed first harvest: second season

Seed cleaning: easy

Planting duration: biennial

Seed insect problem: none noted

Seed shatter: high

Seed size: medium

Seed harvest date: mid August

Seed comments: Produces a copious amount of seed, but plants flower indeterminately and seed shatters explosively as it ripens, making collection of most of the seed difficult.

Herbaria: Specimen data and digital resources from The Consortium of Pacific Northwest Herbaria

Propagation:
1 protocol in the Native Plant Network
Pullman WA Plant Materials Center

Other propagation Information:
No pretreatment required (Rose et al 1998).
Stem cuttings can be propagated in a frame (Mirov 1939).
Direct seeding produced few plants. Stratification did not increase germination (Link 1993).
Reproduces sexually by seed but rosettes subjected to fire may produce clonal rosettes (Paige 1992).

Notes: Gilia aggregata is a tall, rangy plant with spectacular flowers. One of the common names is “skyrocket” and the flowers are certainly reminiscent of fireworks. Hummingbirds are attracted to the flowers. Will bloom all summer if moisture is plentiful. It is a biennial or short-lived perennial, so let it reseed. Should be a great subject in a naturalized setting. We don’t have much data on seed germination, but fall seeding works. Flowers from mid June on throughout the season. Other names include Ipomopsis aggregata, scarlet gilia, skyrocket, fox fire (Skinner et al 2005).

References:
Campbell, Diane R., and Nickolas M. Waser. 1989. Variation in Pollen Flow Within and Among Populations of Ipomopsis aggregata. Evolution 43:1444-1455.

Campbell, Diane R., Nickolas M. Waser, Mary V. Price, Elizabeth A. Lynch, and Randall J. Mitchell. 1991. Components of Phenotypic Selection: Pollen Export and Flower Corolla Width in Ipomopsis aggregata. Evolution 45:1458-1467.

Campbell, Diane R., Nickolas M. Waser, and Mary V. Price. 1996. Mechanisms of Hummingbird-Mediated Selection for Flower Width in Ipomopsis aggregata. Ecology 77:1463-1472.

de Jong, Tom J., Nickolas M. Waser, Mary V. Price, and Richard M. Ring. 1992. Plant Size, Geitonogamy, and Seed Set in Ipomopsis aggregata. Oecologia 89:310-315.

Elam, Diane R., and Yan B. Linhart. 1988. Pollination and Seed Production in Ipomopsis aggregata: Differences Among and Within Flower Color Morphs. American Journal of Botany 75:1262-1274.

Heschel, M. Shane, and Ken M. Paige. 1995. Inbreeding Depression, Environmental Stress, and Population Size Variation in Scarlet Gilia (Ipomopsis aggregata). Conservation Biology 9:126-133.

Juenger, Thomas, and Joy Bergelson. 2000. Factors Limiting Rosette Recruitment in Scarlet Gilia, Ipomopsis aggregata: Seed and Disturbance Limitation. Oecologia 123:358-363.

Kohn, Joshua R., and Nickolas M. Waser. 1985. The Effect of Delphinium nelsonii Pollen on Seed Set in Ipomopsis aggregata, Competition for Hummingbird Pollination. American Journal of Botany 72:1144-1148.

Link, Ellen (ed.). 1993. Native Plant Propagation Techniques for National Parks Interim Guide. USDA, NRCS, Rose Lake Plant Materials Center. East Lansing, MI.

Mayfield, Margaret M., Nickolas M. Waser, and Mary V. Price. 2001. Exploring the "Most Effective Pollinator Principle" with Complex Flowers: Bumblebees and Ipomopsis aggregata. Annals of Botany 88:591-596.

Melendez-Ackerman, Elvia, Diane R. Campbell, and Nickolas Waser. 1997. Hummingbird Behavior and Mechanisms of Selection on Flower Color in Ipomopsis. Ecology 79:2532-2541.

Mirov, N.T., and C.J. Kraebel. 1939. Collecting and Handling Seeds of Wild Plants. Civilian Conservation Corps Forestry Publ. No.5. US Government Printing Office. Washington, DC.

Mitchell, Randall J., and Nickolas M. Waser. 1992. Adaptive Significance of Ipomopsis aggregata Nectar Production: Pollination Sources of Single Flowers. Ecology 73:633-638.

Ouborg, N. Joop, and Jan M. van Groenendael. 1996. Demography, Genetics, or Statistics: Comments on a Paper by Heschell and Paige. Conservation Biology 10:1290-1291.

Paige, Ken N. 1992. The Effects of Fire on Scarlet gilia: an Alternative Selection Pressure to Herbivory? Oecologia 92:229-235.

Paige, Ken M., and M. Shane Heschel. 1996. Inbreeding Depression in Scarlet Gilia: A Reply to Ouborg and van Groenendael. Conservation Biology 10:1292-1294.

Parish, Roberta, Ray Coupe, and Dennis Lloyd. 1996. Plants of Southern Interior British Columbia. Lone Pine Publishing. Vancouver, BC, Canada.

Price, Mary V., and Nickolas M. Waser. 1982. Experimental Studies of Pollen Carryover: Hummingbirds and Ipomopsis aggregata. Oecologia 54:353-358.

Rose, Robin, Caryn E.C. Chachulski, and Diane L. Haase. 1998. Propagation of Pacific Northwest Native Plants. Oregon State University Press, Corvallis, OR.

Skinner, David M., Paul Warnick, Bill French, and Mary Fauci. 2005. Characteristics and Uses of Native Palouse Forbs in Landscaping. USDA NRCS Pullman Plant Materials Center and Palouse Prairie Foundation. Online at http://www.wsu.edu/pmc_nrcs/Docs/Forbs_for_Landscaping.pdf

St. John, Harold. 1963. Flora of Southeastern Washington and of Adjacent Idaho. 3rd edition. Outdoor Pictures. Escondido, CA.

USDA NRCS. 2009. The PLANTS Database (http://plants.usda.gov, 7 August 2009). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

USDA NRCS, Pullman Plant Materials Center. 2005. Seed Weights of Some Palouse Native Species. Pullman Plant Materials Center, Pullman, Washington. Online at http://www.wsu.edu/~pmc_nrcs/Docs/Seed_Weights_Palouse_Native_Species.pdf

Waser, Nickolas M. 1978. Competition for Hummingbird Pollination and Sequential Flowering in Two Colorado Wildflowers. Ecology 59:934-944.

Waser, Nickolas M., and Mary V. Price. 1982. A Comparison of Pollen and Fluorescent Dye Carry-over by Natural Pollinators of Ipomopsis aggregata (Polemoniaceae). Ecology 63:1168-1172.

Waser, Nickolas M., and Mary V. Price. 1989. Optimal Outcrossing in Ipomopsis aggregata: Seed Set and Offspring Fitness. Evolution 43:1097-1109.

Waser, Nickolas M., and Mary V. Price. 1991. Reproductive Costs of Self-Pollination in Ipomopsis aggregata (Polemoniaceae): Are Ovules Usurped? American Journal of Botany 78:1036-1043.

Waser, Nickolas M., Mary V. Price, and Ruth G. Shaw. 2000. Outbreeding Depression Varies among Cohorts of Ipomopsis aggregata Planted in Nature. Evolution 54:485-491.

Wolf, L.L., F. Reed Hainsworth, T. Mercier, and R. Benjamin. 1986. Seed Size Variation and Pollinator Uncertainty in Ipomopsis aggregata (Polemoniaceae). Journal of Ecology 74:361-371.

Links:
Plant Profile from the USDA PLANTS Database
Species information from the University of Washington Herbarium