Island, No. 3289, 3291. Reported by Bennett as B. hirsuta. Collected by Dixon. Pisonia grandis R. Br. Tree about 4 meters high, north shore, South Island, No. 3280. A small grove was observed on the north end of Long Island. This species forms a forest association on many central Pacific atolls where the aboriginal vegetation survives. The clearing necessary for guano mining and the planting of Cocos plantations may have destroyed any former extensive Pisonia forests on Caroline Atoll. The presence of commercial quantities of guano also points to a pre- existing stand of Pisonia if the laying down of such depos- its is indeed accomplished under Pisonia stands (Fosberg, 1957). Collected by Dixon. Portulacaceae Portulaca lutea Sol. Stems clumped, flowers yellow, islet northeast of South Island, No. 3223; clumps 1.5 decimeters high, common, in open coral sand and rubble, second islet south of Nake Is- land, No. 3231; common, Nake Island, No. 3237; in gravel above lagoonshore, common, Long Island (north end), No. 3255; fourth islet north of Bird Island, No. 3257; common in exposed area, South Island, No. 3292. Collected by Dixon. A second species, probably P. oleracea, was recognized by Dixon. This species Was not seen in 1965. For P. lutea see Fig. 2. — Dan have Zygophyllaceae Tribulus cistoides L. In open area, sand, among Tournefortia shrubs, stems to .8 meters long, Long Island, No. 3245. This species is pro- ably distributed by sea birds but was not seen elsewhere on the atoll. A new recoed for the atoll. Simaroubaceae Suriana maritima L.