Simsia calva
Encyclopedia
Simsia calva, more commonly known as the Awnless bush sunflower, is a perennial
or subshrub
that is found in the Southwest United States (Texas
and New Mexico
), as well as Mexico
, the West Indies, and both Central
and South America
.
consist of annuals
, perennials and subshrubs, ranging from anywhere between 20–400 cm (7.9–157.5 ) in height with stems that are either fully erect or ascending. Of the Simsia calva species, the average height ranges from 30 centimetre. The leaves are cauline in their arrangement and can be proximal or whorled. The petioles
are winged and usually form what are considered "discs" when they occasionally fuse with one another at the base. The faces of the leaves are hirsute to scabro-hispid, and are gland-dotted for the most part. The leaves
of S. calva are dilated at the bases, forming fused "discs" with ovate blades measuring 2–8 cm (0.78740157480315–3.1 ) by 1.5–6 cm (0.590551181102362–2.4 ), and even 3-lobed at times.
The head
of most, if not all, Simsia plants, including S. calva are radiate, and are either single, or in groups of two or three heads to form what is known as a corymb.
The peduncles
of Simsia calva rival the length of the base length of the entire plant, nearing around 30 cm (11.8 in) at their largest, and 3 cm (1.2 in) at their smallest. A whorl of involucral bracts are campanulate and range between 5 millimetre in Simsia
, and 10 millimetre to 12 millimetre. The bract below the flower, or phyllary, are around 11-66 in number and can either be condensed or broad. In Simsia calva, the phyllaries are around 21-43 and are arranged subequally to equal.
Simsia
have receptacles that tend to be low convex and paleate, essentially having a scaly covering.
Ray florets are essentially the colorful, flowery portion of the plant. In most Simsia
, the amount of ray florets can be anywhere between non-existent and as many as 45. They vary in colors, being any mixture of orange-yellow, lemon-yellow, pink, purple, or white. Simsia calvatend to have 8-21 ray florets with their colors being orange-yellow, with traces, lining, or fully colored faces of brown or purple.
Disc florets in the overall genus can range anywhere from 12-172 in quantity, however, in contrast to ray florets, disc florets are actually fertile, and bisexual as well. Their colors differ on each part of the floret (i.e., the anthers are black or yellow, and the corollas are the same color as the ray florets). In S. calva, the dis florets are enumerated from around 90-154, with the anthers almost always yellow, scarcely black.
Cypselae are fruits in the Simsia plants that are from inferior ovaries. They tend to be flattened and occasionally hairy. In S. calva, the cypselae are around 4-6mm. In connection with the fruit structures, pappi surround the fruits. Generally absent in Simsia
plants, they are either absent or very fine (4mm) in S. calva as well.
In addition to the habitat that it may live in, S. calva also supports other members of the ecosystem it implements itself within. For large mammals, primarily, the species serves as a food source, albeit it would be a very small factor within a large mammal's diet, such as the white-tailed deer.
Perennial 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...
or subshrub
Subshrub
A subshrub or dwarf shrub is a short woody plant. Prostrate shrub is a similar term.It is distinguished from a shrub by its ground-hugging stems and lower height, with overwintering perennial woody growth typically less than 10–20 cm tall, or by being only weakly woody and/or persisting...
that is found in the Southwest United States (Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
and 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...
), as well as 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...
, the West Indies, and both Central
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
.
Description
Plants in the genus SimsiaSimsia
Simsia is a genus of flowering plants in the family Asteraceae. It comprises 23 species that include annuals, herbaceous perennials, and shrubs...
consist of annuals
Annual plant
An annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...
, perennials and subshrubs, ranging from anywhere between 20–400 cm (7.9–157.5 ) in height with stems that are either fully erect or ascending. Of the Simsia calva species, the average height ranges from 30 centimetre. The leaves are cauline in their arrangement and can be proximal or whorled. The petioles
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
are winged and usually form what are considered "discs" when they occasionally fuse with one another at the base. The faces of the leaves are hirsute to scabro-hispid, and are gland-dotted for the most part. The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
of S. calva are dilated at the bases, forming fused "discs" with ovate blades measuring 2–8 cm (0.78740157480315–3.1 ) by 1.5–6 cm (0.590551181102362–2.4 ), and even 3-lobed at times.
The head
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
of most, if not all, Simsia plants, including S. calva are radiate, and are either single, or in groups of two or three heads to form what is known as a corymb.
The peduncles
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...
of Simsia calva rival the length of the base length of the entire plant, nearing around 30 cm (11.8 in) at their largest, and 3 cm (1.2 in) at their smallest. A whorl of involucral bracts are campanulate and range between 5 millimetre in Simsia
Simsia
Simsia is a genus of flowering plants in the family Asteraceae. It comprises 23 species that include annuals, herbaceous perennials, and shrubs...
, and 10 millimetre to 12 millimetre. The bract below the flower, or phyllary, are around 11-66 in number and can either be condensed or broad. In Simsia calva, the phyllaries are around 21-43 and are arranged subequally to equal.
Simsia
Simsia
Simsia is a genus of flowering plants in the family Asteraceae. It comprises 23 species that include annuals, herbaceous perennials, and shrubs...
have receptacles that tend to be low convex and paleate, essentially having a scaly covering.
Ray florets are essentially the colorful, flowery portion of the plant. In most Simsia
Simsia
Simsia is a genus of flowering plants in the family Asteraceae. It comprises 23 species that include annuals, herbaceous perennials, and shrubs...
, the amount of ray florets can be anywhere between non-existent and as many as 45. They vary in colors, being any mixture of orange-yellow, lemon-yellow, pink, purple, or white. Simsia calvatend to have 8-21 ray florets with their colors being orange-yellow, with traces, lining, or fully colored faces of brown or purple.
Disc florets in the overall genus can range anywhere from 12-172 in quantity, however, in contrast to ray florets, disc florets are actually fertile, and bisexual as well. Their colors differ on each part of the floret (i.e., the anthers are black or yellow, and the corollas are the same color as the ray florets). In S. calva, the dis florets are enumerated from around 90-154, with the anthers almost always yellow, scarcely black.
Cypselae are fruits in the Simsia plants that are from inferior ovaries. They tend to be flattened and occasionally hairy. In S. calva, the cypselae are around 4-6mm. In connection with the fruit structures, pappi surround the fruits. Generally absent in Simsia
Simsia
Simsia is a genus of flowering plants in the family Asteraceae. It comprises 23 species that include annuals, herbaceous perennials, and shrubs...
plants, they are either absent or very fine (4mm) in S. calva as well.
Habitat
S. calva flowers year round in various soils, ranging from sand to clay, and even harder surfaces such as within rocks, on limestone, in prairies, in various types of pine forests, and even along streams and roadsides.In addition to the habitat that it may live in, S. calva also supports other members of the ecosystem it implements itself within. For large mammals, primarily, the species serves as a food source, albeit it would be a very small factor within a large mammal's diet, such as the white-tailed deer.
Range
Simsia calva is prominent throughout Texas, through the trans-Pecos mountains, and leading into New Mexico's southeastern portion.External Links
- USDA NRCS Plant Database
- Simsia Wikipedia PageSimsiaSimsia is a genus of flowering plants in the family Asteraceae. It comprises 23 species that include annuals, herbaceous perennials, and shrubs...
- Image archive of Central Texas Plants
- Flora of North America
- Awnless Bush Sunflower at Texas A&M University