Micronesian Names by Island or Island Groups: Kator, Cator, Mwesor or Panao (southern Mariana Islands; also reported as "kattleknau" on Saipan, see below).

Description: Another Euphorbiaceae species in the genus Claoxylon known from Micronesia is Claoxylon marianum (see above for C. carolinianum); this species was first described from specimens collected in Guam by Charles Gaudichaud-Beaupré, a French scientist who served as botanist on Captain Freycinet's French scientific expedition aboard the Corvette L'Uraine from 1817-1820. Gaudichaud noted that C. marianum closely resembled the Tahiti Claoxylon species, C. taitense (see Safford 1905:231). C. marianum is a relatively small understory, dioecious tree up to about 10 m (~30 ft) tall with a roundish crown. It produces smooth gray stems with elliptic-oblong, alternating, densely compacted leaves about 8-16 cm (~3-6 in) long with serrated margins and secondary veins that are broadly reticulated. The small, inconspicuous male and female flowers occur separately on individual trees, but both male and female flowers are borne in spikes that are greenish-blue in color, waxy and elongate. The fruit is formed as purplish capsules about 7-8 mm thick with three chambers that have a thin orange skin containing one seed in each chamber.

Distribution: As a small, understory woody species, Claoxylon marianum is regarded as endemic to the southern islands of the Mariana archipelago. The tree was first described from the Type specimen collected from Guam in the early part of the 19th century, as noted above. In the earlier part of the 20th century, Kanehira collected this species on Saipan and Rota where he indicated that it could be found in “primary forests at medium altitudes,” and listed “kattleknau” as the local name on Saipan.  In 1946, Fosberg collected a specimen (no. 25043, UH National Herbarium) near the summit of Rota Island at about 450 m elevation that he classified as Claoxylon (later determined by Raulerson to be C. marianum). Parrotta (1994:2) referred to the breadfruit tree, Artocarpus altilis, as “a very common component in a codominant position in association with Claoxylon marianum”and other woody species “in the native limestone rain forests of Rota Island….” In a 1989 U.S. Naval Environmental Impact Statement for Electronic Installations in the Western Pacific, C. marianum (reported as Panao) was reported from a site near the tip of the north-western plateau of Tinian Island. According to the Guam Plant Extinction Prevention Program (GPEPP), an island-wide program dedicated to preventing the extinction of Guam’s rarest plant species, there are now fewer than 200 individuals of C. marianum. Remaining in the wild on Guam where it is a very rare, medium-sized tree found in limestone forest edge areas on this island.

Uses in the Mariana Islands: Claoxylon marianum is reportedly known as Kator (or Mwesor, Cator or Panao)in the Chamorro language (see http://www.gpepp.org/claoxylon-marianum/); for example, Safford (1905:231) listed the local name for this species of Claoxylon as “Panao”on Guam, while Kanehira listed “kattleknau” as the local name on Saipan, and more recently Topping et al. (1975:106) referred to its Chamorro name as “katot…Cf. Panao” (also see Stone 1970). Quattrocchi (2012:985) listed the medicinal use of Claoxylon marianum as a “purgative” [also see Prodromus Systematis naturalis regni Vegetabilis (DC.) 15(2.2): 783. 1866].