Shrubs, scandent, climbing, or erect or trees; evergreen or deciduous, dioecious or monoecious, aromatic, often armed with prickles which are borne on elevated, conical
or pyramidal, corky protruberances. Leaves alternate, trifoliolate to imparipinate or paripinnate; petiole and rachis winged or not; leaflets 3 - 33, subsessile to shortly petiolulate, opposite to alternate, often asymmetric, entire to glandular-serrate. Inflorescence terminal and/or axillary, racemose, cymose or paniculate. Flowers small, unisexual or rarely bisexual. Perianth of 4 to 8, irregularly uniseriate, undifferentiated
segments or biseriate with 4 or 5 outer sepals and 4 or 5 inner petals. Stamens 3 - 5 (-8), free, alternate with petals, in carpeUate flowers reduced to staminodes or absent. Disk flat to pulvinate or obscure. Gynoecium of 1 - 4, sessile or stipitate, distinct or only
partially united carpels, in staminate flowers rudimentary or absent. Ovary 1-locular,
each with 2 collateral pendulous ovules; styles coherent to divergent; stigma capitate,
distinct or coherent. Fruits of 1 to 4, distinct or partially coherent 1-seeded 2-valved
follicles, exocarp firm or fleshy, glandular-punctate, or pustular, red or black, endocatp
cartilaginous, straw coloured, detached or adherent; seeds ovoid to subglobose, black
or reddish, shiny, testa crustaceous, often hanging from opened follicle by a funiculus
on maturity, endosperm fleshy.
Pantropical with some species rarely extending to temperate zones of E. Asia and
one in N. America, ca 220 species, 12 in India.
Literature.
BABU, C.R.(1974) 1977.The genus Zanthoxylum Linn. (Rutaceae) in India. Bull. Bot. Surv. India 16: 48 - 71. BRIZICKY, G. K. (1962). Taxonomic and Nomenclatural notes on Zanthoxylum and Glycosmis (Rutaceae). J. Arn. Arb. 43: 80 - 93. FOSBERG, F.R. (1958) "Zanthoxylum" L., "Xanthoxylum
Mill. and 'Thylax" Raf. Taxon 7: 94 - 96. FOSBERG, F.R.
(1959) Typification of Zanthoxylum. Taxon 8:
103 - 105. HARTLEY, T.G. (1966) A revision of the Malesian species of Zanthoxylum (Rutaceae). J. Arn. Arb. 47: 171 - 211.
Notes.
The taxonomic delimitation and nomenclature of Zanhoxylum L., sensu stricto (with an undifferentiated uniseriate perianth) and its segregate Fagara L. (with biseriate, differentiated perianth) has been a subject of much controversy among earlier
taxonomists. Brizicky (1962) based on his observations on species with perianth structure as transitional to Fagara type proposed that simple perianth of Zanthoxylum was most likely a secondary condition derived by reduction from that of Fagara type due to
abortion of some or all sepals. He considered Fagara as a subgenus under Zanthoxylum.
Hartley (1966) while revising Malesian species of Zanthoxylum demonstrated what was called'a complete transition between Fagara and Zanthoxylum types of perianth' in three staminate specimens of Zanthoxylum dimorphophyllum from China. He, therefore, united both Zanthoxylum and Fagara under one genus. This view was endorsed by Babu (1974) who revised the genus in Indian region, with 13 species including 3 new species viz. Z. burkillianum (from Abor hills (Arunachal Pradesh), Z. pseudoxyphyllum (Manipur) and Z. nepalensis (Nepal).
KEY TO THE SPECIES
1a. Petiole and rachis narrow to broadly winged; perianth of uniseriate or irregularly biseriate 4 - 8, undifferentiated segments
2
b. Petiole and rachis wingless; perianth of biseriate, 4 or 5 sepals and 4 or 5 petals
3
2a. Branchlets ferruginous-pubescent; inflorescence in leaf axils, short, glomerate, paniculate cymes; secondary nerves of leaflets up to 30 pairs, prominent
b. Branchlets glabrous; inflorescence terminal on short, axillary branchlets, spreading, paniculate; Secondary nerves of leaflets up to 20 pairs, more often indistinct
4a. Plants often erect shrubs or small trees up to 10 m high; branchlets with small retrorse, simple prickles; leaves small to medium, up to 30 cm long
5
b. Plants medium to large trees up to 25 or 30 m tall with a long bole and a terminal crown; main stem and
older branches with prickles borne on corky conical protruberances; leaves larger, up to 45 (-60) cm
long
6
5a. Leaves usually digitately 3-foliolate, seldom pinnately 4- or 5-foliolale; branchlets glabrous; gynoecium 1-carpellate
11a. Branchlets, leaves and inflorescences with velvety-pubescent indumentum; leaflets caudate at apex, entire up to middle and slightly crenate above along margins; flowers in lax cymes
b. Branchlets, leaves and inflorescences often glabrous, if pubescent indumentum not as above; leaflets obtusely and shortly acuminate at apex, glandular-crenate to serrate along margins; flowers in dense umbellate clusters
