Aristolochiaceae
Encyclopedia
The Aristolochiaceae, or the Birthwort family, are a family of flowering plant
s with 7 genera and about 400 species belonging to the order Piperales
. The type genus is Aristolochia
L.
, herbaceous plant
s, shrub
s, woody vine
s or even liana
s.
The membranous, cordate simple leaves
are spread out, growing alternately along the stem on leaf stalks. The margins are commonly entire. There are no stipule
s.
The bizarre flower
s are large to medium-sized, growing in the leaf axils. They are bilaterally or radially symmetrical.
which are not part of the large categories of monocots or eudicots.
Some newer classification schemes, such as the Update of the Angiosperm Phylogeny Group
, place the family Aristolochiaceae in the order Piperales
, but it is still quite common, though superseded, for the Aristolochiaceae to be assigned, sometimes with some other families, their own order (Aristolochiales
).
and some of Asarum
contain the toxin aristolochic acid
, which discourages herbivores
and is known to be carcinogen
ic in rat
s. Aristolochia itself is carcinogenic to human
s.
lay their egg
s on pipevine (Aristolochia species), and the larvae
dine on the plant but are not affected by the toxin
, which then offers the adult butterfly protection against predators.
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
s with 7 genera and about 400 species belonging to the order Piperales
Piperales
Piperales is a botanical name for an order of flowering plants. It necessarily includes the family Piperaceae but otherwise has been treated variously over time...
. The type genus is Aristolochia
Aristolochia
Aristolochia is a large plant genus with over 500 species. Collectively known as birthworts, pipevines or Dutchman's pipes, they are the namesake of the family . They are widespread and occur in the most diverse climates. Some species, like A. utriformis and A...
L.
Description
They are mostly 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...
, herbaceous plant
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...
s, shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s, woody vine
Vine
A vine in the narrowest sense is the grapevine , but more generally it can refer to any plant with a growth habit of trailing or scandent, that is to say climbing, stems or runners...
s or even liana
Liana
A liana is any of various long-stemmed, woody vines that are rooted in the soil at ground level and use trees, as well as other means of vertical support, to climb up to the canopy to get access to well-lit areas of the forest. Lianas are especially characteristic of tropical moist deciduous...
s.
The membranous, cordate simple 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....
are spread out, growing alternately along the stem on leaf stalks. The margins are commonly entire. There are no stipule
Stipule
In botany, stipule is a term coined by Linnaeus which refers to outgrowths borne on either side of the base of a leafstalk...
s.
The bizarre 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 are large to medium-sized, growing in the leaf axils. They are bilaterally or radially symmetrical.
Classification
The Aristolochiaceae are magnoliids, a basal group of angiospermsFlowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
which are not part of the large categories of monocots or eudicots.
Some newer classification schemes, such as the Update of the Angiosperm Phylogeny Group
Angiosperm Phylogeny Group
The Angiosperm Phylogeny Group, or APG, refers to an informal international group of systematic botanists who came together to try to establish a consensus on the taxonomy of flowering plants that would reflect new knowledge about plant relationships discovered through phylogenetic studies., three...
, place the family Aristolochiaceae in the order Piperales
Piperales
Piperales is a botanical name for an order of flowering plants. It necessarily includes the family Piperaceae but otherwise has been treated variously over time...
, but it is still quite common, though superseded, for the Aristolochiaceae to be assigned, sometimes with some other families, their own order (Aristolochiales
Aristolochiales
Aristolochiales is an order of flowering plants. It is not recognised in the APG or APG II systems, in which it is considered a synonym of Piperales. It also is not recognized in the Thorne system....
).
Phytochemistry
Many members of AristolochiaAristolochia
Aristolochia is a large plant genus with over 500 species. Collectively known as birthworts, pipevines or Dutchman's pipes, they are the namesake of the family . They are widespread and occur in the most diverse climates. Some species, like A. utriformis and A...
and some of Asarum
Asarum
Asarum is a genus of plants in the birthwort family Aristolochiaceae, commonly known as Wild ginger.- Description :...
contain the toxin aristolochic acid
Aristolochic acid
Aristolochic acids are a family of carcinogenic, mutagenic, and nephrotoxic compounds commonly found in the Aristolochiaceae family of plants, including Aristolochia and Asarum, which are commonly used in Chinese herbal medicine. Aristolochic acid I is the most abundant of the aristolochic acids...
, which discourages herbivores
Plant defense against herbivory
Plant defense against herbivory or host-plant resistance describes a range of adaptations evolved by plants which improve their survival and reproduction by reducing the impact of herbivores. Plants use several strategies to defend against damage caused by herbivores...
and is known to be carcinogen
Carcinogen
A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...
ic in rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s. Aristolochia itself is carcinogenic to human
Human
Humans are the only living species in the Homo genus...
s.
Ecology
Pipevine swallowtail butterfliesSwallowtail butterfly
Swallowtail butterflies are large, colorful butterflies that form the family Papilionidae. There are over 550 species, and though the majority are tropical, members of the family are found on all continents except Antarctica...
lay their egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
s on pipevine (Aristolochia species), and the larvae
Caterpillar
Caterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...
dine on the plant but are not affected by the toxin
Toxin
A toxin is a poisonous substance produced within living cells or organisms; man-made substances created by artificial processes are thus excluded...
, which then offers the adult butterfly protection against predators.
Genera
Subfamily Aristolochioideae
|
Subfamily Asaroideae
|
External links
- International Agency for Research on Cancer evaluation
- Dietary Supplements: Aristolochic Acid, U.S. Food and Drug Administration alerts
- Health Canada advising not to use products labelled to contain Aristolochia