Trichospermum lessertianum comb. n., the correct name for the Cuban species of Trichospermum (Malvaceae, Grewioideae) also found in Mexico and Central America

Abstract The correct name for the Cuban species of Trichospermum Bl. (Malvaceae: Grewioideae) also found in Mexico and Central America is Trichospermum lessertianum (Hochr.) Dorr, comb. n. The name Trichospermum mexicanum (DC.) Baill., incorrectly applied to this Cuban species, should be restricted to a species endemic to western and southern Mexico.


Introduction
Trichospermum Bl. (Malvaceae: Grewioideae, or Tiliaceae) is a genus of ca. 40 species found in tropical America, Asia, and the Pacifi c (Kostermans 1962(Kostermans , 1972. Belotia A. Rich., a generic synonym of Trichospermum, was described from Cuba. Misinterpretations of the legitimacy and identity of its generitype, B. grewiifolia A. Rich., have led authors treating Trichospermum (or Belotia) for various fl oras and revisions to adopt species names that are incorrect. Sorting out this confusion requires determining where Belotia was fi rst published (there are three competing publications); demonstrating that B. grewiifolia was nomenclaturally superfl uous when published; and establishing the identity of the name, Grewia mexicana DC., that should have been adopted as the generitype of Belotia.
Achille Richard published Belotia in three diff erent works that appeared in the 1840s; in volume 10 of Ramón de la Sagra's Historia física, política y natural de la isla de Cuba (Richard 1845: 82; see also Stafl eu and Cowan 1983: no. 10.000), in an unnumbered volume of a French edition of the same work (Richard 1841: 207; see also Stafl eu and Cowan 1983: nos. 9150, 10.002), and in the second volume of Charles d'Orbigny's Dictionnaire universel d'histoire naturelle (Richard 1842: 539; see also Stafl eu and Cowan 1981: no. 7096;Evenhuis 1990). Th e volumes of the French version of de la Sagra's Historia, at least, were issued in parts (livraisons) and these parts were distributed well before the publication dates given on the volumes as a whole (Brizicky 1962: 84-86;see also Stafl eu and Cowan 1983: no. 9150). While the title pages of both the French and Spanish volumes of de la Sagra's Historia that include Belotia have the year 1845, Brizicky (1962: 84-86) determined that the description of Belotia in the French edition actually appeared in a part (livraison) issued in 1841. Th e strongest evidence for this is the review of Richard's contribution to Cuban botany published by Grisebach (1842), which established that the livraison containing Belotia was available by the end of 1841. Th is is the publication date accepted by Stafl eu and Cowan (1983: nos. 9150, 10.002). Th e publication of the second volume of d'Orbigny's Dictionnaire, which included a description of Belotia, followed in 1842. Stafl eu and Cowan (1981: no. 7096) dated this volume 30 July 1842, but Evenhuis (1990) subsequently presented evidence that 20 June 1842 is the latest date at which the livraison containing a description of Belotia could have appeared. (Th e earliest possible, but not probable, date for the publication of this livraison is 24 January 1842). Th e description of Belotia in the Dictionnaire cites the paging and plate number (albeit incorrect) of the Spanish edition of de la Sagra's Historia, which implies that the latter was typeset but presumably not yet distributed. No other evidence has surfaced indicating that the publication of Belotia in the Spanish edition of de la Sagra's Historia was earlier than the date on the title page (i.e., 1845; see also Stafl eu and Cowan 1983: no. 10.000) and without proof establishing some other date, the one appearing in the printed matter must be accepted as correct (see McNeill et al. 2006: Art. 31.1).
Th e fact that Belotia was fi rst published in the French edition of de la Sagra's Historia has nomenclatural implications for the legitimacy of its generitype, B. grewiifolia. In the French edition, B. grewiifolia (Richard 1841: 209) is a superfl uous renaming of Grewia mexicana DC. (1824: 510) as the latter name was placed in synonymy and is the name that should have been adopted (McNeill et al. 2006: Art. 52). Later, in both d'Orbigny's Dictionnaire and in the Spanish edition of de la Sagra's Historia, Richard equivocated with respect to this synonymy. In the former instance, he (1842: 540) wrote "Belotia greviaefolia Rich. (Fl. Cubens p. 82, t. 22), qui est probablement le Grewia mexicana DC." and in the latter (1845: 83) he cited G. mexicana in synonymy with a question mark. Sprague (1921), who revised the genus Belotia, recognized that the Mexican and Cuban species diff ered, but he failed to appreciate that B. grewiifolia was an illegitimate name and he used this name for one of two species he recognized from Cuba. He also confused B. mexicana (DC.) K. Schum. (basionym G. mexicana) with yet a diff erent species occurring in Mexico and Central America. Bullock (1939) continued to use the illegitimate name B. grewiifolia for a species from Cuba, but expanded his concept of this taxon's range to include Central America. He also continued to confuse the identity of B. mexicana. Farr et al. (1979: 91) andRodríguez Fuentes (2000: 31) began to clarify the nomenclatural confusion by recognizing that B. grewiifolia is illegitimate, but the former did so while citing a place of publication (d'Orbigny's Dictionnaire) that if in fact had been the earliest publication would have resulted in the legitimate publication of the name (see McNeill et al. 2006: Art. 52, Note 1, Ex. 12) and the latter although citing the earliest place of publication failed to realize that G. mexicana is not conspecifi c with the Cuban species of Trichospermum.
Although the plate accompanying the description of Belotia grewiifolia is numbered tab. 21, the protologues of both Spanish and French versions of de la Sagra's Historia incorrectly cite tab. 22, which is a plate illustrating Triumfetta grossulariifolia A. Rich. (Malvaceae: Grewioideae). Th e plate caption for B. grewiifolia in the French (Richard 1841: 211), but not the Spanish version (Richard 1845: 84), however, is correctly labeled tab. 21. Although the plates today invariably are bound separately from the text in a folio volume, text and plates originally were probably available at the same time as each livraison of the French version, at least, of de la Sagra's Historia was projected to contain four folio plates accompanied by four sheets of text in octavo (see Stafl eu and Cowan 1983: no. 9150). As early as March-June 1842 there is a published reference (Endlicher 1842: 108; "Belotia A. Richard Flor. cub. 207. t. 22") to the French text of B. grewiifolia and its plate (albeit misnumbered).
Th e type of Grewia mexicana agrees well with the species treated as Trichospermum insigne (Baill.) Kosterm. in the Flora Nova-Galiciana (Fryxell 2001), which has broadly ovate leaf blades with acute apices and a dense and evenly stellate-tomentum below, fl owers with sepals and petals ca. 10 mm long, and capsules 16-18 × 24-28 mm. Th is Mexican species is very distinct from the material of Trichospermum collected in Cuba, which has ovate leaf blades with acuminate to long acuminate apices and a sparse stellate-tomentum below, fl owers with sepals and petals 4-6 mm long, and capsules 8-10 × 10-12 mm. A new combination for the Cuban species of Trichospermum is necessary as the earliest available epithet belongs to a species of Belotia. Th e name T. mexicanum, misapplied to the Cuban species, is here considered to apply to a species endemic to western and southern Mexico that is frequently but incorrectly cited as T. insigne. Distribution. Endemic to western and southern Mexico, where it appears to be restricted to the Pacifi c lowlands and hills from Sinaloa to Oaxaca. Note. McVaugh (2000: 526-527) speculated that the type of Grewia mexicana may have been a garden specimen grown at Madrid from Mexican seed contributed by the Expedición Real.