''Itoa'' is a genus of flowering plants in the family Salicaceae. It is also in the tribe Saliceae. Its native range is southern China to Vietnam, central and eastern Malesia to New Guinea. It is found in China ( Hainan), Maluku Islands, New Guinea,

Sulawesi Sulawesi (), also known as Celebes (), is an island in Indonesia. One of the four Greater Sunda Islands, and the world's eleventh-largest island, it is situated east of Borneo, west of the Maluku Islands, and south of Mindanao and the Sulu Ar ...

and Vietnam.

Description

An evergreen tree with broad leaves, that are alternate, sometimes sub-opposite placed. The leaf blade is pinnate-veined with lateral veins closely set, mostly 1-2 cm apart. The yellow buff flowers, are unisexual, hypogynous (borne below the ovary), The staminate flowers (male flower, flower with stamens but no pistil) are in erect, terminal

panicles A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a panicle are o ...

. The pistillate flowers (a flower containing one or more pistils but no stamens, female flower) has 1 to few in short terminal or axillary racemes. It has bracts and the bracteoles (small bracts) are a pair per pedicel, usually caducous (falling off early). The

sepals 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 The term ''sepalum'' was coined b ...

appearing 3 or 4-merous in bud, in fact to 5-merous at anthesis (at time of flowering), nearly free, valvate, ovate shaped, with base appearing to be cordate (heart-shaped). The staminate flowers have many stamens with filaments free and filiform (thread-like). The

anthers The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

are ellipsoid to oblong in shape, basifixed, connective usually curved, bringing both locules (chambers) to face in same direction (towards the periphery of flower). The pistillate flowers have ovary superior, 1-loculed; placentas are 6-8, rarely 5, filiform and have a woody-like end. The ovules are numerous with 6-8 styles, which are very short, connate (cone-like), forming a short longitudinally ribbed column. The stigmatic branches (4-) 6-8 are spreading or strongly reflexed against the ovary and irregularly palmately lobed. The many staminodes (sterile stamen) are extragynoecial, like the stamens but very much reduced. The seed capsule is ovoid or ellipsoid in shape, large, woody, tomentose (covered in hairs), outer layer probably finally

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 ...

. The valves (5 or) 6-8, are fusiform (rod shaped), splitting from apex and base and remaining attached by woody persistent placental strips. The styles are caducous. It has many seeds, which are arranged vertically in the capsule, they are winged with a broad wing, which is flat, thin, triangular, squarish or rectangular, completely surrounding seed.

Taxonomy

The genus name of ''Itoa'' is in honour of Keisuke Itō (1803–1901) a Japanese physician and biologist, and his grandson Tokutarō Itō (1868–1941), and it was first described and published in Hooker's Icon. Pl. Vol.27 on table 2688 in 1901.

Known species

According to Kew; ''Itoa orientalis'' is grown as an ornamental tree in Australia, Cornwall, UK, and Ireland.Royal Horticultural Society ''Itoa stapfii'' is found in Papua New Guinea.Barry J Conn and Kipiro Q Damas

References

{{Taxonbar, from=Q2029578 Salicaceae Salicaceae genera Plants described in 1901 Flora of Malesia Flora of Vietnam Flora of New Guinea Flora of Henan