Solanum rostratum
Encyclopedia
Solanum rostratum is a species of nightshade (genus Solanum
) that is native to the United States
and northern and central Mexico
. Common name
s include buffalo bur, spiny nightshade, and Texas thistle.
It is an annual
, self-compatible herb
that forms a tumbleweed
. Individual plants reach 1–1.5 m (3.3–4.9 ft) tall, have once or twice pinnatified leaves, and abundant prickles on the stems and leaves. It produces yellow flower
s with pentagonal corollas 2–3.5 cm (0.78740157480315–1.4 in) in diameter and weakly bilaterally symmetric. In its native range S. rostratum is pollinated by medium- to large-sized bee
s including bumblebee
s.
S. rostratum flowers exhibit heteranthery, i.e. they bear two sets of anthers of unequal size, possibly distinct colouration, and divergence in ecological function between pollination and feeding. The fruit
, a berry
, is enclosed by a prickly calyx
. The seed
s are released when the berries dry and dehisce
(split apart) while still attached to the plant.
This species represents one of the latter scientific interests of famed biologist Charles Darwin
, who just over a week prior to his death had ordered seeds from a colleague in America, so as to investigate their heteranthery, a topic he was interested in .
S. rostratum is the ancestral host plant of the Colorado potato beetle
, Leptinotarsa decemlineata, but this pest adopted the potato
, Solanum tuberosum as a new (and more succulent) host, a fact first reported in eastern Nebraska in 1859. It then expanded its range rapidly eastward on potato crops in the next two decades.
Solanum
Solanum, the nightshades, horsenettles and relatives, is a large and diverse genus of annual and perennial plants. They grow as forbs, vines, subshrubs, shrubs, and small trees, and often have attractive fruit and flowers. Many formerly independent genera like Lycopersicon or Cyphomandra are...
) that is native to the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and northern and central 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...
. Common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
s include buffalo bur, spiny nightshade, and Texas thistle.
It is an annual
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...
, self-compatible herb
Herbaceous plant
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
that forms a tumbleweed
Tumbleweed
A tumbleweed is the above-ground part of a plant that, once mature and dry, disengages from the root and tumbles away in the wind. Usually, the tumbleweed is the entire plant apart from the roots, but in a few species it is a flower cluster. The tumbleweed habit is most common in steppe and desert...
. Individual plants reach 1–1.5 m (3.3–4.9 ft) tall, have once or twice pinnatified leaves, and abundant prickles on the stems and leaves. It produces yellow flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s with pentagonal corollas 2–3.5 cm (0.78740157480315–1.4 in) in diameter and weakly bilaterally symmetric. In its native range S. rostratum is pollinated by medium- to large-sized bee
Bee
Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...
s including bumblebee
Bumblebee
A bumble bee is any member of the bee genus Bombus, in the family Apidae. There are over 250 known species, existing primarily in the Northern Hemisphere although they are common in New Zealand and in the Australian state of Tasmania.Bumble bees are social insects that are characterised by black...
s.
S. rostratum flowers exhibit heteranthery, i.e. they bear two sets of anthers of unequal size, possibly distinct colouration, and divergence in ecological function between pollination and feeding. The fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
, a berry
Berry
The botanical definition of a berry is a fleshy fruit produced from a single ovary. Grapes are an example. The berry is the most common type of fleshy fruit in which the entire ovary wall ripens into an edible pericarp. They may have one or more carpels with a thin covering and fleshy interiors....
, is enclosed by a prickly calyx
Sepal
A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...
. The 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 are released when the berries dry and dehisce
Dehiscence (botany)
Dehiscence is the opening, at maturity, in a pre-defined way, of a plant structure, such as a fruit, anther, or sporangium, to release its contents. Sometimes this involves the complete detachment of a part. Structures that open in this way are said to be dehiscent...
(split apart) while still attached to the plant.
This species represents one of the latter scientific interests of famed biologist Charles Darwin
Charles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...
, who just over a week prior to his death had ordered seeds from a colleague in America, so as to investigate their heteranthery, a topic he was interested in .
S. rostratum is the ancestral host plant of the Colorado potato beetle
Colorado potato beetle
The Colorado potato beetle , also known as the Colorado beetle, the ten-striped spearman, the ten-lined potato beetle or the potato bug, is an important pest of potato crops. It is approximately 10 mm long, with a bright yellow/orange body and five bold brown stripes along the length of each...
, Leptinotarsa decemlineata, but this pest adopted the potato
Potato
The potato is a starchy, tuberous crop from the perennial Solanum tuberosum of the Solanaceae family . The word potato may refer to the plant itself as well as the edible tuber. In the region of the Andes, there are some other closely related cultivated potato species...
, Solanum tuberosum as a new (and more succulent) host, a fact first reported in eastern Nebraska in 1859. It then expanded its range rapidly eastward on potato crops in the next two decades.