Dichelostemma capitatum
Encyclopedia
Dichelostemma capitatum (syn. D. pulchellum), called Blue dicks, Purplehead and Brodiaea (alternate spellings, Brodiea, Brodeia ) occur in Arizona
, California
, Oregon
, Utah
, New Mexico
, and northern Mexico
.
growing from an underground corm
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
-like, and dense. It usually contains 2 to 15 flowers, which have a blue, blue-purple, pink-purple, or white perianth
. The flower tube is 3–12 mm and is narrowly cylindrical to campanulate. Flowers have six fertile stamen
s, 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
s. It reproduces from seed and vegetative means in the form of cormlets. The cormlets are attached to the parent corm by stolon
s 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
.
Dichelostemma capitatum occurs from sea level up to 2,300 meters. It inhabits a wide variety of plant communities, including vernal pool
s, valley grassland
, scrub, coniferous forests, and open woodland
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 Dichelostemma capitatum.
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
s, mule deer
, non-native wild pig
s, rabbit
s, and pocket gopher
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). With patience and proper care, these plants can be quite dramatic comes spring.
Indigenous people had several different types of management activities to ensure future corm production at gathering sites:
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. Dichelostemma capitatum 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.
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
, New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
, and northern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
.
Subspecies
- Dichelostemma capitatum subsp. capitatum
- Dichelostemma capitatum subsp. pauciflorum
Description
Dichelostemma capitatum is an herbaceous perennialPerennial plant
A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...
growing from an underground corm
Corm
A corm is a short, vertical, swollen underground plant stem that serves as a storage organ used by some plants to survive winter or other adverse conditions such as summer drought and heat ....
to a height of as much as 60 cm. It has 2–3 leaves which are 10–40 cm long. The inflorescence is head
Capitulum
The term Capitulum can refer to several things:*In botany, a type of flower head where the bracts are located under the basis, such as a daisy's*Also in botany, the top of a Sphagnum moss plant with compact clusters of young branches....
- or umbel
Umbel
An umbel is an inflorescence which consists of a number of short flower stalks which are equal in length and spread from a common point, somewhat like umbrella ribs....
-like, and dense. It usually contains 2 to 15 flowers, which have a blue, blue-purple, pink-purple, or white perianth
Perianth
The term perianth has two similar but separate meanings in botany:* In flowering plants, the perianth are the outer, sterile whorls of a flower...
. The flower tube is 3–12 mm and is narrowly cylindrical to campanulate. Flowers have six fertile stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...
s, deeply notched, lanceolate, white, angled inward, slightly reflexed at tip, with outer filaments wider at the base. It has a twisted and fleshy peduncle
Peduncle (botany)
In botany, a peduncle is a stem supporting an inflorescence, or after fecundation, an infructescence.The peduncle is a stem, usually green and without leaves, though sometimes colored or supporting small leaves...
, a set of membranous, petal-like stamen appendages around the anthers, and angular black seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s. It reproduces from seed and vegetative means in the form of cormlets. The cormlets are attached to the parent corm by stolon
Stolon
In biology, stolons are horizontal connections between organisms. They may be part of the organism, or of its skeleton; typically, animal stolons are external skeletons.-In botany:...
s 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
Ecological succession
Ecological succession, is the phenomenon or process by which a community progressively transforms itself until a stable community is formed. It is a fundamental concept in ecology, and refers to more or less predictable and orderly changes in the composition or structure of an ecological community...
species in chaparral
Chaparral
Chaparral is a shrubland or heathland plant community found primarily in the U.S. state of California and in the northern portion of the Baja California peninsula, Mexico...
.
Dichelostemma capitatum occurs from sea level up to 2,300 meters. It inhabits a wide variety of plant communities, including vernal pool
Vernal pool
Vernal pools, also called vernal ponds or ephemeral pools, are temporary pools of water. They are usually devoid of fish, and thus allow the safe development of natal amphibian and insect species...
s, valley grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
, scrub, coniferous forests, and open woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
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 Dichelostemma capitatum.
Uses
Corms have been gathered by Native AmericansNative Americans in the United States
Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...
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
American black bear
The American black bear is a medium-sized bear native to North America. It is the continent's smallest and most common bear species. Black bears are omnivores, with their diets varying greatly depending on season and location. They typically live in largely forested areas, but do leave forests in...
s, mule deer
Mule Deer
The mule deer is a deer indigenous to western North America. The Mule Deer gets its name from its large mule-like ears. There are believed to be several subspecies, including the black-tailed deer...
, non-native wild pig
Pig
A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig, its ancestor the wild boar, and several other wild relatives...
s, rabbit
Rabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...
s, and pocket gopher
Pocket gopher
The pocket gophers are burrowing rodents of the family Geomyidae. These are the "true" gophers, though several ground squirrels of the family Sciuridae are often called gophers as well...
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). With patience and proper care, these plants can be quite dramatic comes spring.
Management
thumbIndigenous 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. Dichelostemma capitatum 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.