''Dipterostemon'' is a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

s in the family Asparagaceae. Its only species is ''Dipterostemon capitatus'', synonym ''Dichelostemma capitatum'', known by the common names blue dicks, purplehead and brodiaea (alternately spelled brodiea and brodeia), native to the Western United States (particularly

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

Oregon Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. T ...

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

, and

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ke ...

) and northwest

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

Description

''Dipterostemon capitatus'' is an herbaceous

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wid ...

growing from an underground

corm A corm, bulbo-tuber, or bulbotuber is a short, vertical, swollen underground plant stem that serves as a storage organ that some plants use to survive winter or other adverse conditions such as summer drought and heat (perennation). The word ' ...

to a height of as much as 60 cm. It has 2–3 leaves which are 10–40 cm long. The inflorescence is head- or

umbel In botany, an umbel is an inflorescence that consists of a number of short flower stalks (called pedicels) that spread from a common point, somewhat like umbrella ribs. The word was coined in botanical usage in the 1590s, from Latin ''umbella'' "p ...

-like, and dense. It usually contains 2 to 15 flowers, which have a blue, blue-purple, pink-purple, or white

perianth The perianth (perigonium, perigon or perigone in monocots) is the non-reproductive part of the flower, and structure that forms an envelope surrounding the sexual organs, consisting of the calyx (sepals) and the corolla ( petals) or tepals when ...

. The flower tube is 3–12 mm and is narrowly cylindrical to campanulate. Flowers have six fertile stamens, deeply notched, lanceolate, white, angled inward, slightly reflexed at tip, with outer filaments wider at the base. It has a twisted and fleshy peduncle, a set of membranous, petal-like stamen appendages around the anthers, and angular black

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

s. It reproduces from seed and vegetative means in the form of cormlets. The cormlets are attached to the parent corm by stolons and are sessile, produced in the axils of the old leaf bases on the mature corm. Plants thrive in open disturbed environments, and are a common post-fire succession species in chaparral. Flowering peaks in March.Dichelostemma capitatum
at iNaturalist ''D. capitatus'' occurs from sea level up to 2,300 meters. It inhabits a wide variety of plant communities, including

vernal pool Vernal pools, also called vernal ponds or ephemeral pools, are seasonal pools of water that provide habitat for distinctive plants and animals. They are considered to be a distinctive type of wetland usually devoid of fish, and thus allow the safe ...

s, valley

grassland A grassland is an area where the vegetation is dominated by grasses ( Poaceae). However, sedge ( Cyperaceae) and rush ( Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur na ...

, scrub,

coniferous forest Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All exta ...

s, and open

woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (se ...

s. It seems not to colonize after fire by seed, but rather by cormlets. After fire, plants are exposed to unshaded environments with little brush competition, and vigorously flower in open environments with increased soil nutrients. Grasslands that have been burned may exhibit thousands of plants where none have appeared in recent years. Corms may sit for a decade or more and wait for fire or other favorable environmental conditions before breaking ground. Suppression of fire may cause increased shade and plant competition and decrease population numbers of ''D. capitatus''.

Taxonomy

The species was first described by

George Bentham George Bentham (22 September 1800 – 10 September 1884) was an English botanist, described by the weed botanist Duane Isely as "the premier systematic botanist of the nineteenth century". Born into a distinguished family, he initially studie ...

in 1857 as ''Brodiaea capitata''. In 1868, Alphonso Wood moved it to the genus '' Dichelostemma'' as ''Dichelostemma capitatum''. In 1912,

Per Axel Rydberg Per Axel Rydberg (July 6, 1860 – July 25, 1931) was a Swedish-born, American botanist who was the first curator of the New York Botanical Garden Herbarium. Biography Per Axel Rydberg was born in Odh, Västergötland, Sweden and emigrated t ...

moved it to ''Dipterostemon'' as ''Dipterostemon capitatus''. Most sources continued to use Wood's placement in ''Dichelostemma'', including the ''Flora of North America'', which however noted that it was "quite distinct from other species in the genus" and that it was perhaps "best treated as its own genus". In 2017, restoration of ''Dipterostemon'' as a monotypic genus was proposed. This has been accepted by sources such as Plants of the World Online and the Jepson Flora Project.

Subspecies

Three subspecies are accepted: *''Dipterostemon capitatus'' subsp. ''capitatus'' *''Dipterostemon capitatus'' subsp. ''lacuna-vernalis'' (L.W.Lenz) R.E.Preston *''Dipterostemon capitatus'' subsp. ''pauciflorus'' (Torr.) R.E.Preston (common name - desert hyacinthMojave Desert Wildflowers, Pam MacKay, 2nd ed., 2013, )

Uses

Corms have been gathered by Native Americans in California, parts of the Great Basin, and the Southwest. These corms were an important starch source in their diet. California tribes dug and continue to dig the corms before flowering, during flowering, or after seeding depending on the tribe and individual family. Traditional gathering sites were visited annually, and there were gathering tracts with different kinds of corms and bulbs owned and maintained by particular families. Corms are eaten by animals such as

black bear Black bear or Blackbear may refer to: Animals * American black bear (''Ursus americanus''), a North American bear species * Asian black bear (''Ursus thibetanus''), an Asian bear species Music * Black Bear (band), a Canadian First Nations group ...

mule deer The mule deer (''Odocoileus hemionus'') is a deer indigenous to western North America; it is named for its ears, which are large like those of the mule. Two subspecies of mule deer are grouped into the black-tailed deer. Unlike the related whi ...

, non-native wild

pig The pig (''Sus domesticus''), often called swine, hog, or domestic pig when distinguishing from other members of the genus '' Sus'', is an omnivorous, domesticated, even-toed, hoofed mammal. It is variously considered a subspecies of ''Sus ...

s, rabbits, and

pocket gopher Pocket gophers, commonly referred to simply as gophers, are burrowing rodents of the family Geomyidae. The roughly 41 speciesSearch results for "Geomyidae" on thASM Mammal Diversity Database are all endemic to North and Central America. They are ...

s. As some of the corms are eaten, others are dispersed. The animals detach the cormlets, which aerates the soil, prepares the seedbed, thins the plant population, and leaves some cormlets behind. Once separated, corms may take less time to reach flowering size. Although slow to flowering starting from seeds, it is sometimes used in horticulture. The flowers mix well in native beds, especially when contrasted against other California native species such as California poppies (''

Eschscholzia californica ''Eschscholzia californica'', the California poppy, golden poppy, California sunlight or cup of gold, is a species of flowering plant in the family Papaveraceae, native to the United States and Mexico. It is cultivated as an ornamental plant ...

''). With patience and proper care, these plants can become quite dramatic come spring.

Management

Indigenous people had several different types of management activities to ensure future corm production at gathering sites: #breaking off cormlets from the harvested parent corms and replanting them #sparing whole plants #harvesting the corms after plants have gone to seed and dumping the seeds in the hole #burning areas #irrigation Periodic digging and thinning of the corms or separating the cormlets, and replanting them may have enhanced plant numbers and densities. Digging corms acts as a form of tillage, which will increase the size of the gathering tract, aerate the soil, lower weed competition, and prepare the seedbed to increase seed germination rates. ''Dipterostemon capitatus'' populations require periodic disturbance to maintain and increase their populations; therefore, indigenous harvesting regimes may help maintain populations. Populations that become overcrowded and show reduced vigor can be divided and separated.

Propagation

Seeds sown in the fall usually readily germinate and do not need special treatment. If planting seeds, they will take several years to reach flowering size. Propagation by corms is much easier.

References

External links