Rhus
Content
Description
Erect or scandent shrubs, trees, or lianas, sometimes hemi-epiphytic, mostly deciduous.
Leaves spiral, imparipinnate, trifoliolate, unifoliolate, rarely simple (R. borneensis), petioled;
Inflorescences paniculate, rarely racemose and few-flowered, terminal, axillary, sometimes pseudoterminal (then terminal bud of the twig present).
Flowers unisexual or bisexual (plants dioecious, sometimes polygamous, or polygamo-dioecious).
Petals 5, imbricate, glabrous, rarely hairy on the inner surface.
Stamens 5;
Ovary 1-celled, abortive in ♂;
Seed with the testa adhering to the endocarp or free from it;
Distribution
Asia-Tropical, Australasia: Queensland (Queensland present), West Pacific Is present, temperate zones of both hemispheres extending in the subtropics and tropics present
Widely distributed in the temperate zones of both hemispheres extending in the subtropics and tropics, abundant in seasonal and dry areas, but surprisingly poorly occurring in Australia where it is only represented in Queensland by 2 spp., of which 1 endemic (and a closely related monotypic genus Rhodos-phaera); throughout Malesia, also in West Pacific Is.
Since ENGLER (1883) revised the genus it has not been monographed in its entirety. The number of species is difficult to estimate, but will probably run to c. 200.
Since ENGLER (1883) revised the genus it has not been monographed in its entirety. The number of species is difficult to estimate, but will probably run to c. 200.
Taxonomy
Recently two American authors proposed to split the genus. GILLIS l.c. recognized again Toxicodendron on generic rank with 3 American and 2 Asian spp., but also 1 American-Asian sp. BARKLEY l.c. (1942) distinguished a genus Duckera BARKLEY, which he based on Rhus sect. Melanocarpeae ENGL.; but ENGLER had already based this on the genus Melanococca Bl. 1850, so that Duckera is superfluous and illegitimate. It has already been reduced to Rhus by BRIZICKY (1963) who is in favour of keeping the genus Rhus in the large sense, with which I agree.
The genus has been subdivided into a few subgenera and sections, but I refrain from an opinion as this can only be considered in the scope of an entire revision of the genus.
The genus has been subdivided into a few subgenera and sections, but I refrain from an opinion as this can only be considered in the scope of an entire revision of the genus.
Uses
No uses known of native species. Growing the Sino-japanese lacquer yielding R. vernicifera DC. has been unsuccessful (BURKILL) and suggestions to attempt this quite unrealistic (HEYNE).
Notes
Among the species are unifoliolate ones. Their leaflet is articulated. R. borneensis has, however, really simple leaves lacking any articulation.
Citation
BARKLEY 1937 – In: Ann. Mo. Bot. Gard.: 417
MARCH. 1869: Rév. Anacard.: 84 & 179
DING HOU 1978 – In: Blumea: 34
Engl. 1881 – In: Bot. Jahrb.: 378
GILLIS 1971 – In: Rhodora: 161
MILLER 1768: Gard. Dict, ed. 8
LINNE 1883 – In: DC., Mon. Phan. 4: 376
BARKLEY 1937 – In: Ann. Mo. Bot. Gard.: 312
LINNE 1753 – In: Sp. Pl.: 265
BRIZICKY 1963 – In: J. Arn. Arb.: 62