Delphinium glaucum Larkspur
Common Names
pied-d’alouette glauque
dauphinelle glauque
Brown’s larkspur (GBIF)
duncecap larkspur
giant larkspur
Hooker’s larkspur
mountain larkspur (Flora of NA)
pale larkspur (NatureServe Explorer)
pale-flowered Brown’s larkspur
Sierra larkspur (USDA, Ecological Atlas of Denali’s Flora)
tall larkspur (VASCAN, Flora of BC)
tower larkspur (ITIS)
western larkspur
*There are so many common names, and almost no floras or sources agree. I just call it larkspur, highlighting some of the more popular floras accepted names.
Synonyms
Delphinium brownii
Delphinium occidentale ssp. cucullatum
Delphinium scopulorum
Delphinium scopulorum var. glaucum
Delphinium splendens
Subspecies
No direct subspecies
Genus: Delphinium
Family: Ranunculaceae
Order: Ranunculales
taxonomic hierarchy
Duration – Growth Habit
Perennial – Forb/herb
Identification and Information
Delphinium glaucum, commonly known as tall larkspur, Sierra larkspur (and others; see note under common names above), is a tall perennial herb in the buttercup family (Ranunculaceae) that grows from a thick, tough rootstock and woody caudex. The stems are typically 0.5-1.3 meters tall (can grow up to 3 meters) and are green to reddish-purple, glabrous, and hollow. The leaves grow along the stem alternately and are palmately divided into 5 broadly wedge-shaped segments, which are 2-3 times lobed or toothed. The leaves are also sparsely hairy, dark green above, lighter green below, and reduced in size higher up the stem.
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The inflorescence is a terminal raceme of 10-90 flowers (up to 140). The flowers are on a 1-3 cm pedicel, trumpet-shaped, sparsely hairy, bilaterally symmetric, linear bracts, and have a large spur to the back. The sepals are the more prominent feature, bluish to purple or lavender, 17-24 mm long, forward-pointing to spreading. The lower 2 lower petals cover the stamens. The flowers mature into 9-20 mm long follicles (3.5-4.5 times longer than they are wide) with straight beaks about 3 mm long. The seeds are winged and pale to dark brown.
The flowers resemble the smaller, bilaterally symmetric monkshood (Aconitum delphiniifolium), although they lack the signature hood.
Flowering in summer to early fall.
Uses
For information only (typically historical) – I take no responsibility for adverse effects from the use of any plant.
The entire plant is highly poisonous, especially the seeds. It can be fatal to humans and animals.
Larkspur, including Delphinium glaucum, is recognized for its high toxicity rather than for any edible or medicinal benefits. This plant, especially prevalent in the western United States, poses a significant risk to livestock due to its potential to cause neuromuscular paralysis in cattle and less frequently in sheep and horses, primarily before the plant matures. The seeds and new growth are particularly toxic parts of the plant. While certain Delphinium species have been used to derive parasiticidal products for external application, extreme caution is necessary. The plant contains potent cardiotoxic alkaloids, which can be absorbed through the skin, making even external uses potentially harmful. Research by the USDA emphasizes the importance of understanding the toxicological aspects of larkspur species to mitigate poisoning risks in grazing areas, highlighting ongoing efforts to develop management strategies and antidotes for affected livestock.
Distribution and Habitat
Map data from the Global Biodiversity Information Facility (GBIF), NatureServe Explorer, and Kew. It’s worth noting that Kew lists D. glaucum as native to Manitoba.
Delphinium glaucum is native to western North America, including Alaska, western Canada, and most US states from the Rocky Mountains westward. NatureServe Explorer lists it as a non-native species to Manitoba, and Flora of North America includes Saskatchewan as a non-native province.
It grows in open coniferous forests, thickets, bogs, meadows, tundra, and streambanks from montane to alpine zones between sea level and 3200 m elevation.
Classification
| Rank | Scientific Name (Common Name) |
|---|---|
| Kingdom | Plantae (plantes, Planta, Vegetal, plants) |
| Subkingdom | Viridiplantae (green plants) |
| Infrakingdom | Streptophyta (land plants) |
| Superdivision | Embryophyta |
| Division | Tracheophyta (vascular plants, tracheophytes) |
| Subdivision | Spermatophytina (spermatophytes, seed plants, phanérogames) |
| Class | Magnoliopsida |
| Superorder | Ranunculanae |
| Order | Ranunculales |
| Family | Ranunculaceae (buttercups, boutons d’or, crowfoot) |
| Genus | Delphinium L. (larkspur) |
| Species | Delphinium glaucum S. Watson (tower larkspur, mountain larkspur, Sierra larkspur) |
References and Further Reading
Guidebook
Pratt, V. E. (1989). Field Guide to Alaskan Wildflowers: Commonly Seen Along Highways and Byways (p. 7). Alaskakrafts, inc.
Johnson, D., Kershaw, L., & MacKinnon, A. (2020). Plants of the Western Forest: Alaska to Minnesota Boreal and Aspen Parkland (3rd ed., p. 129). Partners Publishing. ISBN 978-1772130591.
Brandenburg, D. M. 2010. National Wildlife Federation Field Guide to Wildflowers of North America. Sterling Publishing. (p. 467)
Schofield, J. 2020. Alaska’s Wild Plants: A Guide to Alaska’s Edible Harvest (Revised Edition) (p. 179). Alaska Northwest Books.
Classification and Taxonomy
Integrated Taxonomic Information System (ITIS). (n.d.). Delphinium glaucum. Retrieved April 7, 2024, from https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=18458#null
Database of Vascular Plants of Canada (VASCAN). (n.d.). Delphinium glaucum. Retrieved April 7, 2024, from https://data.canadensys.net/vascan/taxon/8481?lang=en
USDA Plants Database. (n.d.). Delphinium glaucum. Retrieved April 7, 2024, from https://plants.usda.gov/home/plantProfile?symbol=DEGL3
Uses/Toxicity
USDA Agricultural Research Service. (n.d.). Larkspur (Delphinium spp.). Poisonous Plant Research. Retrieved April 7, 2024, from https://www.ars.usda.gov/pacific-west-area/logan-ut/poisonous-plant-research/docs/larkspur-delphinium-spp/
Map and Distribution
GBIF. (n.d.). Delphinium glaucum. Retrieved April 7, 2024, from https://www.gbif.org/species/3033694
NatureServe Explorer. (n.d.). Delphinium glaucum. Retrieved April 7, 2024, from https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.131763/Delphinium_glaucum
Plants of the World Online (POWO). (n.d.). Delphinium glaucum. Retrieved April 7, 2024, from https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:275700-2
Description and Information
Flora of North America. (n.d.). Delphinium glaucum. Retrieved April 7, 2024, from http://floranorthamerica.org/Delphinium_glaucum
E-Flora BC. (n.d.). Delphinium glaucum. Retrieved April 7, 2024, from https://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Delphinium%20glaucum&redblue=Both&lifeform=7
Alaska Center for Conservation Science. (n.d.). Delphinium glaucum. Retrieved April 7, 2024, from https://ecologicalatlas.uaf.edu/index.php/browse-plant-species/atlas-page/?nps_id=656
