Botanical Survey of India | Flora of India

JSP Page

Trees, rarely shrubs, with perulate buds; usually deciduous, rarely evergreen. Leaves petiolate, palmately 3-7-lobed or entire or pinnately 3-7(9)- foliate. Inflorescence on 2-4, leafy, terminal branches or on leafless lateral or terminal branches. Petals equal to or shorter than sepals, often yellowish- green. Disc rarely reduced or absent, often intrastaminal, rarely extrastaminal or having stamens in the middle. Anthers introrse; in male flowers exserted; in bisexual flowers inserted. Ovules collateral or superposed. Seed in each locule very often solitary through abortion.

Temperate N. America. N.W. Africa, Asia and Malesian islands; ca 118 species, 17 in India.

Literature. BANERJEE M.L. & S. DAS (1971) Acers in Nepal. Indian For. 97(5): 243-250. MURRAY. E. (1974) Himalayan maples. Kalmia 6: 2-8.



KEY TO THE SPECIES


1a. Plants having both lobed and unlobed leaves. 10. Acer osmastonii
b. Plants having either lobed or unlobed leaves, both conditions not present together 2
2a. Leaves not lobed 3
b. Leaves lobed 9
3a. Inflorescence racemose, pendent 4
b. Inflorescence paniculate or corymbose 6
4a. Leaf margins subentire or finely serrulate; samaras indistinctly stalked or almost sessile; stalk 0.2 cm long 14. Acer sikkimense
b. Leaf margins serrate or deeply serrate; samaras distinctly stalked; stalk 0.7-5 cm long 5
5a. Samaras 1.8 - 2.5 cm long; fruit stalk 0.7 - 1 cm long; petiole 2.5 cm long; leaves glabrous or glabrate beneath; flowers 5-merous 6. Acer hookeri
b. Samaras 2.5 cm long; fruit stalk 3 - 5 cm long; petiole 5 - 7 cm long; leaves canescent or villous beneath; flowers 4-merous 15. Acer stachyophyllum
6a. Leaf apex caudate-acuminate; inflorescence lateral 7
b. Leaf apex acuminate; inflorescence terminal 8
7a. Petals 2.5 - 8 cm long 8. Acer laurinum
b. Petals less than 2 mm long 13. Acer pinnatinervium
8a. Upper surface of leaves green, lower surface glaucous; petiole 2 - 7 cm long, usually ca 1/3rd of the lammina length 9. Acer oblongum
b. Upper surface of leaves olive green, lower surface brownish; petiole 0.7 - 1.8 cm long; usually ca 1/8th of the lamina length. 7. Acer laevigatum
9a. Leaves 3-lobed, lobatious sometimes obsolete 10
b. Leaves 3-lobed. sometimes 7 lobed, the lower lobations not prominent 12
10a. Apex of leaf lobes cuspidate-serrulate, long caudate, margin deeply dentate 1. Acer acuminatum
b. Apex of leaf lobes acuminate, margin entire or obsoletely serrate 11
11a. Samaras 2 - 3 cm long, glabrous; leaves 5 - 9 x 9 - 11 cm, undersurface glabrescent or glabrous 12. Acer pentapomicum
b. Samaras 5 - 8 cm long, villous; lcaves 13 - 15 x 14 - 24 cm; undersurface of leaves along the nerves villous, glabrescent. 17. Acer thomsonii
12a. Margins of leaves entire 4. Acer cappadocicum
b. Margins of leaves serrate to remotely serrate 13
13a. Samaras erect, the angles of divergence 90° or less than that 14
b. Samaras slanting, the angles of divergence more than 90° 16
14a. Under surface of leaves glabrous or glabrescent except at the axils of nerves which are bearded 2. Acer caesium
b. Undersurface of leaves pubescent 15
15a. Leaf margin inciso-serrate; apex caudate; inflorescence racemose, erect; samaras 3 x 1 - 1.5 cm 5. Acer caudatum
b. Leaf margin remotely serrate; apex acuminate; inflorescence lateral. fasciculate-racemose, pendulous; samaras 4 - 5 x 1.5 - 2 cm 16. Acer sterculiaceum
16a. Leaf lobes deltoid. apex caudate-acuminate, leaf margins deeply serrate; samara-nutlets elliptic-oblong 11. Acer pectinatum
b. Leaf lobes ovate-caudate or lanceolate-caudate, leaf margins subentire to serrulate; samara-nutlets orbicular 3. Acer campbellii


JSP Page
  • Search