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Pterospermum acerifolium



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Tree from India, where it is grown for shade and for valuable timber similar to oak and teak.

Interesting Facts

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Common Names

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Click on the language to view common names.

Common Names in English:

Bayur, Bayur Tree, Dinnerplate Tree, Maple Leaved Bayur, Mayeng, Pterospermum

Common Names in Hindi:

कनक चम्पा

Common Names in Oriya:



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Family Malvaceae

Herbs, shrubs , or less often trees ; indumentum usually with peltate scales or stellate hairs . Leaves alternate, stipulate , petiolate ; leaf blade usually palmately veined, entire or various lobed . Flowers solitary, less often in small cymes or clusters , axillary or subterminal , often aggregated into terminal racemes or panicles, usually conspicuous , actinomorphic , usually bisexual (unisexual in Kydia) . Epicalyx often present, forming an involucre around calyx, 3- to many lobed. Sepals 5, valvate , free or connate . Petals 5, free, contorted, or imbricate, basally adnate to base of filament tube . Stamens usually very many, filaments connate into tube; anthers 1-celled. Pollen spiny . Ovary superior, with 2-25 carpels, often separating from one another and from axis; ovules 1 to many per locule; style as many or 2 × as many as pistils, apex branched or capitate. Fruit a loculicidal capsule or a schizocarp, separating into individual mericarps, rarely berrylike when mature (Malvaviscus) ; carpels sometimes with an endoglossum (a crosswise projection from back wall of carpel to make it almost completely septate . Seeds often reniform , glabrous or hairy , sometimes conspicuously so.

About 100 genera and ca. 1000 species: tropical and temperate regions of N and S Hemisphere; 19 genera (four introduced ) and 81 species (24 endemic, 16 introduced) in China.

Molecular studies have shown that the members of the Bombacaceae, Malvaceae, Sterculiaceae, and Tiliaceae form a very well-defined monophyletic group that is divided into ten also rather well-defined clades, only two of which correspond to the traditional families Bombacaceae and Malvaceae. Some of the remaining groups are included entirely within either of the remaining families but others cut across the traditional divide between the Sterculiaceae and Tiliaceae. A majority of authors , most notably Bayer and Kubitzki (Fam. Gen. Vasc. Pl. 5: 225-311. 2003), has favored including everything within a greatly enlarged Malvaceae, and treating the individual clades as subfamilies. The alternative view is that the individual clades should be treated as a series of ten families: Bombacaceae (Bombacoideae), Brownlowiaceae (Brownlowioideae), Byttneriaceae (Byttnerioideae), Durionaceae (Durionoideae), Helicteraceae (Helicteroideae), Malvaceae (Malvoideae), Pentapetaceae (Dombeyoideae), Sparrmanniaceae (Grewioideae), Sterculiaceae (Sterculioideae), and Tiliaceae (Tilioideae) (Cheek in Heywood et al. , Fl. Pl. Fam. World. 201-202. 2007) . For the present treatment, we prefer to retain the familiar, traditional four families, so as to maintain continuity with the treatments in FRPS, and to await a consensus on the two alternative strategies for dealing with the very widely accepted clades.

The traditional Malvaceae coincides exactly with one of the major clades. The only possible problem is the relationship with the Bombacaceae, which also has primarily 1-loculed anthers, and some authorities have suggested that the Bombacaceae should be included within the Malvaceae.

Members of the Malvaceae are important as fiber crops (particularly cotton, Gossypium) . Young leaves of many species can be used as vegetables, and species of Abelmoschus and Hibiscus are grown as minor food crops. Many species have attractive flowers and an ever-increasing selection is grown as ornamentals . Several have been cultivated for a very long time, particularly species of Hibiscus, and some of these are not known in the wild.[1]

Genus Pterospermum

Trees or shrubs , stellate velutinous or scurfy and scaly . Leaves simple ; stipules linear to palmately fimbriate, sometimes forming nectaries, caducous ; petiole short; leaf blade lobed or not, leathery, base often oblique , margin entire or serrate, apex sometimes truncate ; juvenile leaves sometimes much larger, petiole long, leaf blade often with peltate base and prominently palmately lobed. Inflorescence axillary , 1-flowered or cymose and 1-5-flowered. Flowers bisexual ; epicalyx lobes usually 3, usually distant from calyx, entire, fimbriate, or palmately lobed, rarely absent, caducous. Calyx 5(or 6) -lobed, divided nearly to base, usually spreading to ± reflexed , caducous. Petals 5, white or yellow, often erect . Androgynophore present, very short, glabrous . Stamens 15, in 5 groups of 3 alternating with staminodes; filaments connate into tube , free at top; anthers 2-celled, cells parallel, connective pointed ; staminodes 5, filiform , longer and thicker than filaments. Ovary 5-locular; ovules 4-22 per locule; style clavate or filiform; stigma longitudinally 5-grooved. Fruit a schizocarp, cylindric or ovoid , angular or rounded , usually woody, sometimes leathery, dehiscent into 5 loculicidal mericarps when mature . Seeds 2 to many per locule, with long, oblong , membranous wing ; endosperm scanty or absent; cotyledons usually plicate , simple. 2n = 38.

Between 18 and 40 species: tropical and subtropical Asia; nine species (five endemic) in China.[2]

Physical Description

Species Pterospermum acerifolium

Big trees ; bark smooth . Branchlets densely velutinous when young. Stipules linear ; petiole robust , striate ; leaf blade nearly orbicular or oblong , sometimes ± lobed , 24-34 × 14-29 cm, leathery, abaxially densely yellowish and gray stellate velutinous, adaxially sparsely hairy or glabrous , base cordate, margin entire or crenate, apex truncate , nearly rounded , or pointed ; juvenile leaves palmately lobed, peltate. Flowers solitary, fragrant; epicalyx lobes fimbriate or palmately divided. Sepals linear-oblong, ca. 9 × 0.7 cm, abaxially densely yellow-brown stellate velutinous, adaxially white villous . Petals white, linear-oblong, slightly cuneate, slightly shorter than sepals, glabrous. Staminodes clavate , hairy. Ovary oblong, 5-angular; ovules many per locule. Capsule woody, cylindrical, stipitate , obscurely 5-grooved, 10-15 × 5-5.5 cm, reddish brown velutinous, glabrescent , base tapering, apex rounded. Seeds many per locule, obliquely ovate , flat, wing large and thin, brown, smooth. [source]

Flowers: Flower Color: near white, white


Size: over 40' tall.


Forested slopes ; 1200-1700 m [3].


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Culture: Space 15-20' apart.

Soil: Minimum pH: 6.1 • Maximum pH: 7.5

Sunlight: Sun Exposure: Sun to Partial Shade.

Temperature: Cold Hardiness: 10a, 10b, 11. (map)


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Publishing author : Willd. Publication : Sp. Pl., ed. 4 [Willdenow] 3(1): 729 1800

Similar Species

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Members of the genus Pterospermum

ZipcodeZoo has pages for 1 species, subspecies, varieties, forms, and cultivars in this genus:

P. acerifolium (Bayur)

More Info

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Further Reading

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Data Sources

Accessed through GBIF Data Portal March 17, 2008:



  1. Ya Tang, Michael G. Gilbert & Laurence J. Dorr "Malvaceae". in Flora of China Vol. 12 Page 240, 264,299, 302. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at [back]
  2. Ya Tang, Michael G. Gilbert & Laurence J. Dorr "Pterospermum". in Flora of China Vol. 12 Page 302, 303, 327. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at [back]
  3. "Pterospermum acerifolium". in Flora of China Vol. 12 Page 327, 328. Missouri Botanical Garden Press. Online at [back]
Last Revised: 2014-11-21