Platostoma

Platostoma is a genus of flowering plants in the mint family, Lamiaceae, first described as a genus in 1818. It is native to tropical parts of Africa, southern Asia, Papuasia, and Australia. Mesona and Acrocephalus has been known as its synonyms.

A widely consumed species in this genus is Platostoma palustre (synonyms Mesona chinensis, M. elegans, and M. procumbens), or xiancao (仙草) in Mandarin, sian-chháu (仙草) in Taiwanese, leung fun cho (涼粉草) in Cantonese, sương sáo in Vietnamese, and cincau in Indonesian and Malay. It is eaten as a snack in drinks, or set as a gel and served as a grass jelly.

In Indonesia the Platostoma palustre leaf is used to make a black jelly; there is also an instant powder variety available.

Species
51 species are accepted.
 * 1) Platostoma africanum P.Beauv — tropical Africa, southern India, Lesser Sunda Islands in Indonesia
 * 2) Platostoma albiflorum Suddee, A.J.Paton & J.Parn. – Thailand
 * 3) Platostoma annamense (G.Taylor) A.J.Paton — Vietnam, Thailand, Cambodia
 * 4) Platostoma axillaris (Benth.) A.J.Paton — Assam
 * 5) Platostoma becquerelii Suddee & A.J.Paton — Cambodia
 * 6) Platostoma busbanianum Suddee, A.J.Paton & J.Parn. – Thailand
 * 7) Platostoma calcaratum (Hemsl.) A.J.Paton — southern China, northern Indochina
 * 8) Platostoma cambodgense Suddee & A.J.Paton — Vietnam, Thailand, Cambodia, Laos
 * 9) Platostoma clausum (Merr.) A.J.Paton — Culion Island in Philippines
 * 10) Platostoma cochinchinense (Lour.) A.J.Paton — southern China, Indochina, Java, Sumatra
 * 11) Platostoma coeruleum (R.E.Fr.) A.J.Paton — Angola, Zambia
 * 12) Platostoma coloratum (D.Don) A.J.Paton — Yunnan, eastern Himalayas, northern Indochina
 * 13) Platostoma denticulatum Robyns — central Africa from Cameroon east to Tanzania and south to Angola
 * 14) Platostoma dilungense (Lisowski & Mielcarek) A.J.Paton — Zaïre, Tanzania, Zambia, Malawi
 * 15) Platostoma elongatum (Benth.) A.J.Paton — Sri Lanka, southern India
 * 16) Platostoma fastigiatum A.J.Paton & Hedge — Madagascar
 * 17) Platostoma fimbriatum A.J.Paton — Thailand
 * 18) Platostoma gabonense A.J.Paton — Cameroon, Gabon, Tanzania
 * 19) Platostoma glomerulatum A.J.Paton & Hedge — Madagascar
 * 20) Platostoma grandiflorum Suddee & A.J.Paton — eastern Indochina
 * 21) Platostoma helenae (Buscal. & Muschl.) ined.. — Mozambique
 * 22) Platostoma hemratianum Suddee, Puudjaa & Kiewbang – Thailand
 * 23) Platostoma hildebrandtii (Vatke) A.J.Paton & Hedge — Kenya, Tanzania
 * 24) Platostoma hispidum (L.) A.J.Paton — Southeast Asia, southern China, Assam, New Guinea
 * 25) Platostoma intermedium A.J.Paton — Thailand
 * 26) Platostoma kerrii Suddee & A.J.Paton — Thailand, Cambodia
 * 27) Platostoma lanceolatum (Chermsir. ex Murata) A.J.Paton — Thailand
 * 28) Platostoma laxiflorum A.J.Paton & Hedge — Madagascar
 * 29) Platostoma leptochilon Robyns — Zaïre
 * 30) Platostoma longicorne (F.Muell.) A.J.Paton — Queensland, New Guinea
 * 31) Platostoma madagascariense (Benth.) A.J.Paton & Hedge — Madagascar
 * 32) Platostoma mekongense Suddee — Thailand
 * 33) Platostoma menthoides (L.) A.J.Paton — Sri Lanka, southern India
 * 34) Platostoma montanum (Robyns) A.J.Paton — Zaïre, Tanzania, Rwanda, Burundi
 * 35) Platostoma ocimoides (G.Taylor) A.J.Paton — Thailand, Cambodia
 * 36) Platostoma ovatum Suddee, A.J.Paton & J.Parn. – Thailand
 * 37) Platostoma palniense (Mukerjee) A.J.Paton — southern India
 * 38) Platostoma palustre (Blume) A.J.Paton — Southeast Asia, southern China, Assam, Bangladesh, New Guinea
 * 39) Platostoma parnellianum Suddee, A.J.Paton & Kiewbang – Thailand
 * 40) Platostoma rotundifolium (Briq.) A.J.Paton — tropical and southern Africa
 * 41) Platostoma rubrum Suddee & A.J.Paton — Thailand, Laos
 * 42) Platostoma siamense (Murata) A.J.Paton — Thailand
 * 43) Platostoma stoloniferum (G.Taylor) A.J.Paton — Thailand, Laos
 * 44) Platostoma strictum (Hiern) A.J.Paton — Zaïre, Angola, Zambia, Malawi
 * 45) Platostoma taiwanense S.S.Ying – Taiwan
 * 46) Platostoma taylorii Suddee & A.J.Paton — Thailand, Cambodia
 * 47) Platostoma tectum A.J.Paton — Thailand, Cambodia, Laos
 * 48) Platostoma tenellum (Benth.) A.J.Paton & Hedge — Madagascar
 * 49) Platostoma thymifolium (Benth.) A.J.Paton & Hedge — Madagascar
 * 50) Platostoma tridechii Suddee — Thailand
 * 51) Platostoma verbenifolium (Watt ex Mukerjee) A.J.Paton — Assam, Bangladesh, Arunachal Pradesh, Myanmar