| Annonaceae | |
|---|---|
 | |
| Annona squamosa fruit | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Magnoliids |
| Order: | Magnoliales |
| Family: | Annonaceae Juss. |
| Genera | |
See text
| |
| Synonyms | |
Hornschuchiaceae J. Agardh
Monodoraceae J. Agardh[1] | |
Annonaceae, also called the custard apple family[2][3] is a family of flowering plants consisting of trees, shrubs or rarely lianas.[3] With about 2300 to 2500 species and more than 130 genera,[4] it is the largest family in Magnoliales. Only five genera, Annona, Rollinia, Uvaria, Melodorum and Asimina produce edible fruits.[4] Its type genus is Annona. The family is concentrated in the tropics, with few species found in temperate regions. About 900 species are Neotropical, 450 are Afrotropical, and the other species Indomalayan.
Compared to the species from the Neotropics, very little is known about many species from Indomalaya. Only a few attempts have been made for thephylogeny-based reclassification of the family, and those have been hampered by the Neotropic bias in the available information, with the most of the work having been done on genera and tribes.[5]
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[edit]Description
Mostly tropical, some mid-latitude, deciduous or evergreen trees and shrubs, some lianas, with aromatic bark, leaves, and flowers.[3]
- Stems, stalks and leaves
- Bark is fibrous and aromatic. Pith septate (fine tangential bands[5] divided by partitions) to diaphragmed (divided by thin partitions with openings in them).[3]
- Branching distichous (arranged in two rows/on one plane) or spiral.[6]
- Leaves are alternate, two-ranked,[6] simple, pinnately veined, and have leaf stalks. Stipules absent.[3]
- Flowers
- Flower stalks are axillary to (on the opposite side of shoot from) leaf scars on old wood and sometimes from leaves on new shoots. The flowers are usuallytrimerous; borne singly or in compound inflorescences; bisexual and rarely unisexual. The receptacle might become enlarged, elevated or flat. The outer whorlsare inserted below the ovaries, and have valvate (overlapping) or imbricate (nonoverlapping) segments. Usually two to four persistent sepals that are distinct or connate (fused) at the base. Six petals in two unequal whorls of three with larger outer whorls and fleshier inner whorls that might share the same nectar glands, or six to fifteen petals, with impressed veins on their inner face. Ten to twenty (or many more) stamens inserted below the ovary, spirally arranged and forming a ball or flat-topped mass with short and stout filaments and linear to oblong anthers which face outward and open longitudinally. Each flower can have from one to many pistils, distinct to connate, with stigmas distinct. Marginal placentation, each pistil bearing one locule, with one to many ovules. Style short and thick, with terminal stigma.[3]
- Fruits and seeds
- Fruits are distinct (berries) or coalesce (into syncarps). Seeds are one to many per pistil; have a fleshy and usually brightly colored cover, have ruminate endosperm (nutritive tissue surrounding the embryo) and are oily.[3]
[edit]Systematics
Monophyly and inter-familial systematics have been well supported for Annonaceae by a combination of morphological and molecular evidence.[7] The APG II system places Annonaceae as most closely related to the small Magnoliid family Eupomatiaceae.
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Combined plastid DNA marker and morphological character analysis of Anaxagorea and other Annonaceae and basal angiosperm genera suggest that Anaxagorea is an ancestral clade, sister to the rest of the family. This may confirm the hypothesis that morphological traits shared with other Magnoliales species (such as 2-ranked phyllotaxis, monosulcate pollen, and laminate stamens) represent ancestral characters, while derived characters observed in other genera have evolved independently multiple times. These analyses also support a biogeographic history in which Annonaceae, and perhaps other basal angiosperm clades, originated in South America during the Cretaceous, radiating due to migration events throughout Africa to Asia and Central to North America.[8] [9]
Guatteria, with its approximately 265 species, is the largest genus of Annonaceae, and might be broken into three small genera based on molecular characters from multiple locations.[10]
Tribe Saccopetaleae is another group of Annonaceae that is awaiting review as recent molecular studies suggest that this tribe is not monophyletic at all.[11]
[edit]Uses
[edit]Food
The large, edible, pulpy fruits of some members typically called "anona" by Spanish and Portuguese speaking people of the family's Neotropical range, include species of Annona: custard apple (A. reticulata), cherimoya (A. cherimola), soursop/guanábana/graviola (A. muricata), sweetsop (A. squamosa), ilama(A. diversifolia), soncoya (A. purpurea), atemoya (a cross between A. cherimola and A. squamosa); and biriba (Rollinia deliciosa, which may require reclassification under Annona.[1]). The names of many of those fruits are sometimes used interchangeably. Recently, consumption of the neotropical annonaceous plant Annona muricata (soursop, graviola, guanabana) has been strongly associated as a causal agent in "atypical Parkinsonsism." The causative agent, annonancin, is present in many of the annonaceae. It is thought to be responsible for up to 70% of Parkinsonian conditions in Guadeloupe. Exposure is typically through traditional food and "natural" medicines.[12][13][14][15]
Asimina triloba (American pawpaw, prairie banana) has an Eastern U.S. distribution, and is currently under agricultural investigation as a commercial crop.[16]
[edit]Medical
The bark, leaves and roots of some species are used in folk medicines. Pharmaceutical research has found antifungal, bacteriostatic, antimalarial, and especially cytostatic capability of some chemical constituents of the leaves and bark. A large number of chemical compounds, including flavonoids, alkaloids and acetogenins, have been extracted from the seeds and many other parts of these plants. Flavonoids and alkaloids have shown antibacterial properties, and have been used for treatment of medical conditions, such as skin disease, intestinal worms and inflammation of the eye. Pharmaceutical products are currently in animal and human cell-line trials.[17][18] Acetogenins are thought to have anti-HIV and anti-cancer effects. A wide variety of products have been developed and are available for cancer treatment.[19]
[edit]Insecticides
Flavonoids and alkaloids contained in the leaves and bark of several species of the family have shown insecticidal properties.[19]
[edit]Other
- Some species of the family, such as Cananga odorata (ylang-ylang) also have aromatic oil and are used for perfumes or spices.[5]
- The strong bark is used for carrying burdens in the Amazon Rainforest[5] and for wooden implements, such as tool handles and pegs.[19] The wood is valued as firewood.[5]
- Yellow and brown dyes.[19]
- Some species are also grown as ornamental plants, especially the Indian species Polyalthia longifolia pendula.
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