Sagittaria sanfordii
Encyclopedia
Sagittaria sanfordii is an uncommon species of flowering plant in the water plantain family
known by the common name valley arrowhead. It is endemic to California
, where it is known from a few scattered occurrences on the North Coast and in the Central Valley. Many occurrences previously noted in the Central Valley and in southern California have been extirpated
as the plant's aquatic habitat has been lost to human activity. This is an aquatic
perennial herb growing from a spherical tuber
. The leaves are variable in shape, not necessarily sagittate, or shaped like arrowhead
s, as the leaves of many other Sagittaria
are. Leaves may grow up to 25 centimeters long from the underwater stem. The plant is monoecious
, with individuals bearing both male and female flowers. The inflorescence
which rises above the surface of the water is a raceme
made up of several whorls of flowers, the lowest node bearing female flowers and upper nodes bearing male flowers. The flower is up to 3.5 centimeters wide with white petals. The male flowers have rings of stamen
s at the centers. Female flowers each have a spherical cluster of pistils
which develops into a head of tiny fruits.
Alismataceae
The water-plantains are a family of flowering plants, comprising 11 genera and between 85-95 species. The family has a cosmopolitan distribution, with the greatest number of species in temperate regions of the Northern Hemisphere...
known by the common name valley arrowhead. It is endemic to 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...
, where it is known from a few scattered occurrences on the North Coast and in the Central Valley. Many occurrences previously noted in the Central Valley and in southern California have been extirpated
Local extinction
Local extinction, also known as extirpation, is the condition of a species which ceases to exist in the chosen geographic area of study, though it still exists elsewhere...
as the plant's aquatic habitat has been lost to human activity. This is an aquatic
Aquatic plant
Aquatic plants are plants that have adapted to living in aquatic environments. They are also referred to as hydrophytes or aquatic macrophytes. These plants require special adaptations for living submerged in water, or at the water's surface. Aquatic plants can only grow in water or in soil that is...
perennial herb growing from a spherical tuber
Tuber
Tubers are various types of modified plant structures that are enlarged to store nutrients. They are used by plants to survive the winter or dry months and provide energy and nutrients for regrowth during the next growing season and they are a means of asexual reproduction...
. The leaves are variable in shape, not necessarily sagittate, or shaped like arrowhead
Arrowhead
An arrowhead is a tip, usually sharpened, added to an arrow to make it more deadly or to fulfill some special purpose. Historically arrowheads were made of stone and of organic materials; as human civilization progressed other materials were used...
s, as the leaves of many other Sagittaria
Sagittaria
Sagittaria is a genus of about 30 species of aquatic plants whose members go by a variety of common names, including arrowhead, duck potato, iz-ze-kn, katniss, kuwai , swan potato, tule potato, and wapato...
are. Leaves may grow up to 25 centimeters long from the underwater stem. The plant is monoecious
Plant sexuality
Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....
, with individuals bearing both male and female flowers. The inflorescence
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...
which rises above the surface of the water is a raceme
Raceme
A raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...
made up of several whorls of flowers, the lowest node bearing female flowers and upper nodes bearing male flowers. The flower is up to 3.5 centimeters wide with white petals. The male flowers have rings of stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...
s at the centers. Female flowers each have a spherical cluster of pistils
Gynoecium
Gynoecium is most commonly used as a collective term for all carpels in a flower. A carpel is the ovule and seed producing reproductive organ in flowering plants. Carpels are derived from ovule-bearing leaves which evolved to form a closed structure containing the ovules...
which develops into a head of tiny fruits.