''Aegialitis'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of two shrubby

mangrove A mangrove is a shrub or tree that grows mainly in coastal saline water, saline or brackish water. Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen a ...

species, with one native to

Southeast Asia Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...

and the other native to

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

and

Papua New Guinea Papua New Guinea, officially the Independent State of Papua New Guinea, is an island country in Oceania that comprises the eastern half of the island of New Guinea and offshore islands in Melanesia, a region of the southwestern Pacific Ocean n ...

Description

The two species of the genus are woody mangrove shrubs or small trees that grow up to 2 to 3 m tall. The

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

species have leafy stems with leathery leaves arranged alternately or spirally. The

leaf margin A leaf (: leaves) is a principal appendage of the plant stem, stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leav ...

s are entire and have parallel veins. The hermaphroditic flowers are pollinated by

Hymenoptera Hymenoptera is a large order of insects, comprising the sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are parasitic. Females typi ...

Lepidoptera Lepidoptera ( ) or lepidopterans is an order (biology), order of winged insects which includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organ ...

, and

Diptera Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advance ...

. Flowers are arranged in terminal cymose racemous

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

s. Individual flowers have five

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 Etymology The term ''sepalum'' ...

s arranged in a fused tube around the white gamopetalous corolla that has five petals fused into a short tube. The

androecium The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

consists of five

stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s that are attached near the base of the corolla tube. The superior

gynoecium Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl (botany), whorl of a flower; it consists ...

has five

carpel Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more ...

s, each with a 1-celled

pistil Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl (botany), whorl of a flower; it consists ...

and unilocular

ovaries The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are endocr ...

. Fruit are

dehiscent Dehiscence is the splitting of a mature plant structure along a built-in line of weakness to release its contents. This is common among fruits, anthers and sporangia. Sometimes this involves the complete detachment of a part. Structures that op ...

and have a spongy

mesocarp Fruits are the mature ovary or ovaries of one or more flowers. They are found in three main anatomical categories: aggregate fruits, multiple fruits, and simple fruits. Fruitlike structures may develop directly from the seed itself rather tha ...

. Unlike other mangrove species, the members of ''Aegialitis'' generally do not have

aerial root Aerial roots are Root, roots growing above the ground. They are often Plant development#Adventitious structures, adventitious, i.e. formed from nonroot tissue. They are found in diverse plant species, including epiphytes such as orchids ('' ...

s.Australian Institute of Marine Science. (2003)
Club Mangrove
. ''Field Guide to the Mangroves of Queensland''. Accessed online: 5 January 2009.

Taxonomy

The genus ''Aegialitis'' was described by

Robert Brown Robert Brown may refer to: Robert Brown (born 1965), British Director, Animator and author Entertainers and artists * Washboard Sam or Robert Brown (1910–1966), American musician and singer * Robert W. Brown (1917–2009), American printmaker ...

in his 1810 work ''

Prodromus Florae Novae Hollandiae et Insulae Van Diemen ''Prodromus Florae Novae Hollandiae et Insulae Van Diemen'' (Prodromus of the Flora of New Holland and Van Diemen's Land) is a book by the botanist Robert Brown Robert Brown may refer to: Robert Brown (born 1965), British Director, Animator and ...

'' when he described the single species ''A. annulata''. The second species was described by

William Roxburgh William Roxburgh FRSE FRCPE Linnean Society of London, FLS (3/29 June 1751 – 18 February 1815) was a Scottish people, Scottish surgeon and botanist who worked extensively in India, describing species and working on economic botany. He is known ...

in the 1830s. A genus of

grass Poaceae ( ), also called Gramineae ( ), is a large and nearly ubiquitous family (biology), family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos, the grasses of natural grassland and spe ...

es was given the same genus name in 1820 by

Carl Bernhard von Trinius Carl Bernhard von Trinius (6 March 1778, Eisleben – 12 March 1844, St. Petersburg) was a German-born botanist and physician. He studied medicine at several universities, earning his medical doctorate at the University of Göttingen in 180 ...

and later renamed ''

Rostraria ''Rostraria'' is a genus of plants in the Poaceae, grass family, native primarily to Eurasia and North Africa with one species native to South America. Hairgrass is a common name. These grasses are sometimes included in genus ''Koeleria''. ; Sp ...

''.Flora of Pakistan
''Aegialitis''
Accessed online 5 January 2009. There have been several opinions on the proper placement of the genus in relation to the rest of the Plumbaginaceae, though most authors have noted its distinct characteristics make it difficult to place properly. In 1968 Igorj Alexandrovich Linczevski suggested that the genus be included in its own

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

family, the Aegialitidaceae. The Plumbaginaceae has historically been divided into either two subfamilies or two tribes and each approach has offered a different perspective of the proper taxonomic relationship in the family. Through cladistic analysis using both genetic and morphological characteristics, studies have concluded that ''Aegialitis'' is the sister

taxon In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

to the rest of its subfamily (Staticoideae) and thus has been assigned to the monotypic tribe Aegialitideae, which is sister to the tribe Staticeae (including the genera ''

Acantholimon ''Acantholimon'' (prickly thrift) is a genus of small flowering plants within the plumbago or leadwort family, Plumbaginaceae. They are distributed from southeastern Europe to central Asia, and also cultivated elsewhere in rock gardens. Form The ...

'', '' Armeria'', '' Goniolimon'', '' Limoniastrum'', and '' Limonium''). The genus name, ''Aegialitis'', derives from the Greek, ''aegialos'', ("seashore"), referring to where species of this genus are found.

Distribution and habitat

The two species of the genus are native to Southeast Asia and Australia, but their distribution ranges do not overlap. ''A. annulata'' is found along the northern coasts of Australia from

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

through the

Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

and into

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

and along the coastline of Papua New Guinea. ''A. rotundifolia'' is found on the shorelines of the

Andaman Sea The Andaman Sea (historically also known as the Burma Sea) is a marginal sea of the northeastern Indian Ocean bounded by the coastlines of Myanmar and Thailand along the Gulf of Martaban and the west side of the Malay Peninsula, and separated f ...

and the

Bay of Bengal The Bay of Bengal is the northeastern part of the Indian Ocean. Geographically it is positioned between the Indian subcontinent and the Mainland Southeast Asia, Indochinese peninsula, located below the Bengal region. Many South Asian and Southe ...

from

Orissa Odisha (), formerly Orissa ( the official name until 2011), is a state located in Eastern India. It is the eighth-largest state by area, and the eleventh-largest by population, with over 41 million inhabitants. The state also has the thir ...

Mergui Myeik (, or ; , ; , , ; formerly Mergui, ) is a rural city in Tanintharyi Region, Myanmar, located in the extreme south of the country on the coast off an island on the Andaman Sea. , the estimated population was over 209,000. ''World Gazett ...

and on the

Andaman Islands The Andaman Islands () are an archipelago, made up of 200 islands, in the northeastern Indian Ocean about southwest off the coasts of Myanmar's Ayeyarwady Region. Together with the Nicobar Islands to their south, the Andamans serve as a mari ...

.Saenger, P. (2002).
Mangrove Ecology, Silviculture, and Conservation
'' Springer Publishing. pp. 26. .Weber-El Ghobary, Magda O. (1984). The systematic relationships of ''Aegialitis'' (Plumbaginaceae) as revealed by pollen morphology. ''Plant Systematics and Evolution'', 144(1): 53-58. The distribution of these two species with respect to the other members of the Plumbaginaceae is suggestive of the evolutionary history and

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

placement of ''Aegialitis''. Several authors have discovered evidence for three distinct southern migrations of this mostly

Northern Hemisphere The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined by humans as being in the same celestial sphere, celestial hemisphere relative to the invariable plane of the Solar ...

family, the first of which remained isolated and evolved into the existing members of this genus. This hypothesized migration and evolutionary history explains the more primitive breeding system characteristics and morphology in this genus in relation to the rest of the family.Lledó, M. D., Karis, P. O., Crespo, M. B., Fay, M. F., and Chase, M. W. (2001). Phylogenetic position and taxonomic status of the genus ''Aegialitis'' and subfamilies Staticoideae and Plumbaginoideae (Plumbaginaceae): evidence from plastid DNA sequences and morphology. ''Plant Systematics and Evolution'', 229: 107-124. As with other mangrove species, the habitat preferred by the members of this genus are sandy or rocky soils in the more saline environment of the mangroves toward the sea. The species are thus

halophytic A halophyte is a salt-tolerant plant that grows in soil or waters of high salinity, coming into contact with saline water through its roots or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs, and seashores. ...

References

External links

* {{Taxonbar, from1=Q4687565, from2=Q21214912 Plumbaginaceae Mangroves Plumbaginaceae genera Taxa named by Robert Brown (botanist, born 1773)