Poikilospermum

Poikilospermum is a tropical genus of shrubs or tall woody climbers, consisting of at least four accepted species and another 23 species with unresolved taxonomic status. The plants are found from India and China (Yunnan), the Sino-Himalayan region to Malesia and New Guinea including the Bismarck Archipelago. Some of the plants are used by people.

Poikilospermum
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Rosales
Family: Urticaceae
Tribe: Urticeae
Genus: Poikilospermum
Zipp. ex Miq.
Species

between 4 & 41, see text

Common names in the genus include the Chinese 锥头麻属 (zhui tou ma shu) and 陈家瑞 (chen jiarui or chen chia-jui),[1] and the Khmer krâpë rô.[2]

Classification

The classification of the genus has been dynamic and is linked to the status of the family Cecropiaceae. At present, consensus places it in the family Urticaceae.[3][4] One recent phylogenetic study placed it in a clade with Urtica, though two slightly older studies placed it as a sister clade to the Cecropieae (the former Cecropiaceae s. str.) and Urticaeae (Urticaceae s. antiq.).[4] Older, nonphylogenetic, work placed the genus in Cecropiaceae, a family regarded as intermediate between Urticeae and Moraceae[1]

Taxonomic history

Alexander Zippelius (1797-1828) is given authorship of the genus, publishing in Annales Musei Botanici Lugduno-Batavi (Amsterdam), 1: 203, in 1864. His work superseded that of Friedrich Anton Wilhelm Miquel (1811-1871). In 1978, Berg placed it in Cecropiaceae. Most recent work has been by Datwyler & Weiblen (2004), Zerega et al. (2005), and Hadiah et al. (2008) place the genus in Urticaceae.

Description

Members of Poikilospermum are shrubs or tall woody climbers (also known as lianas).[1] The petiolate leaves are alternate; their stipules are often caducous, intrapetiolar, connate, and leathery; their veins are often prominently pinnate; cystoliths occur adaxially in circular groups, abaxially along veins, either punctiform or linear. The inflorescences are solitary and axillary dichotomously branched cymes, they are unisexual (the plants are dioecious). The glomerules are capitate and either on swollen peduncular receptacles (in P. subgen. Ligulistigma, continental Asia group), in agglomerations, or are free (in P. subgen. Poikilospermum, E Malaysia group). The male flowers are with 2-4 perianth lobes, free or slightly connate; there are two to four stamens, the filaments are straight (in P. subgen. Ligulistigma) or inflexed; a rudimentary ovary is present. The female flowers have four perianth lobes, and are clavate-tubular and decussate-imbricate. The ovary in this genus is enclosed, with a short style, a capitate or ligulate (in P. subgen. Ligulistigma) stigma; the ovule is orthotropous. The seeds have little or no endosperm. The cotyledons are ovate.

Distribution and habitat

Plants of the genus occur naturally from Sino-Himalayan region (including NE India and Yunnan) over to Malesia, including Vietnam, Malaysia and the Philippines, and on to the Bismarck Archipelago.[1] In China there are 3 species. Species often have high moisture requirement, occurring in Monsoon forests and rain forests, often near streams or other we places, at altitudes ranging from 500m to 1800m. In Cambodia P. suaveolens grows in the undergrowth of dense forests.[2]

Human use

One species is used to a ties (as in to tie things together).[2]

Selected species

These four names are accepted, but one synonym and 37 names have been unassessed to taxonomic status.[3]

  • Poikilospermum lanceolatum (Trècul) Merrill
  • Poikilospermum naucleiflorum (Roxburgh ex Lindley) Chew
  • Poikilospermum suaveolens (Blume) Merrill
  • Poikilospermum tonkinense (Drake) Merrill

References

  1. Flora Of China: Poikilospermum, eFloras (2008), published on the Internet http://www.efloras.org [accessed 18 September 2012], Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA, http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=126288
  2. Dy Phon Pauline, 2000, Plants Used In Cambodia, printed by Imprimerie Olympic, Phnom Penh
  3. "The Plant List: Poikilospermum". Retrieved 17 April 2014.
  4. Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 12, July 2012 [and more or less continuously updated since], http://www.mobot.org/MOBOT/research/APweb/, accessed 18 September 2012
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