Duncan M. Porter

PSIDIUM (MYRTACEAE) IN THE GALAPAGOS ISLANDS

The three insular taxa of Psidium are described, and a key to them is provided. The relationships of the endemic Psidium galapageium are discussed, and P. galapageium var. howellil is described as new. In a survey of the Myrtaceae for the Flora of the Galapagos Islands, it has become increasingly obvious that three taxa of Psidium are present in the archipelago. The first is P. guajava L., the cultivated guava, which has escaped and become naturalized on several of the islands. The second is the endemic P. galapageium Hook. f., a common tree of the transition and Scalesia forests of the larger islands. The third proves to be an undescribed variety of P. galapageium. These three taxa may be distinguished by means of the following key: a. Flowers ca 2.5 cm in diam, in 1(-3)-flowered dichasia; buds 7-10 mm long; leaves ovate to ovate-lanceolate, slightly inequilateral, 5-14 cm long, 2-6 cm wide, persistent. 1. P. guajava aa. Flowers ca 1-1.5 cm in diam, solitary; buds 4-5 mm long; leaves elliptic to ovate or occasionally suborbicular, equilateral, 1.8-5.5 cm long, 0.9-2.6 cm wide, deciduous. b. Buds unlobed, closed at anthesis except for a terminal pore, distally glabrous; calyx opening by a circumscissile calyptra 2a. P. galapageium var. galapageium bb. Buds 5-lobed apically, open at anthesis, tomentose; calyx splitting irregu

Two New Species of Protium (Burseraceae) From Central America

Examination of the above-cited type material, plus a more recent collection [PANAMA. CHIRIQUI: Denuded premontane rain forest between Pinola and Quebrada Seco on the Chiriquicito-Caldera Trail. Tree 20 cm diameter; apparently armed with conical corky spines, or unarmed. 21 April 1968. Kirkbride & Duke 1024 (MO)], shows this taxon to fall within the generic limits of Zanthoxylum. Following his type description, Standley indicated that, In its trimerous flowers the tree is perhaps anomylous in the genus Amyris, to which it seems best referred.-Duncan M. Porter, Missouri Botanical Garden.

The flowers of Trattinnickia aspera (Burseraceae) discovered.

Although Swart (1942: 426) wrote of Trattinnickia aspera (Stanley) Swart as having flowers 3-merous, flowering specimens of this Panamanian endemic tree heretofore apparently have never been collected. All exsiccatae cited by Swart in his monograph [Standley 40815 (US); Standley 41161 (US, holotype; US, isotype)] have been examined by the junior author. None proved to be in flower; Standley 40815 is sterile, and Standley 41161 is fruiting. All other collections of this species seen from F, GH, MO, and US, likewise, have been sterile or in fruit. Consequently, the description of Trattinnickia aspera given in the Flora of Panama (Porter, 1970) lacks floral characters.