New Taxa and Combinations in the Ocotea helicterifolia (Lauraceae) Species Group

Abstract

In the course of preparing a treatment of the Ocotea helicterifolia group for Flora Mesoamericana, the existing treatment was found to be outdated. A review of the group is here presented and includes the description of the following new species: O. congregata van der Werff, O. corrugata van der Werff, O. gordonii van der Werff, and O. patula van der Werff, as well as the following new combinations: 0. betazensis (Mez) van der Werff, O. bourgeauviana (Mez) van der Werff, O. purpurea (Mez) van der Werff, and O. tonii (Lundell) van der Werff. A key to the species of the group is presented, new synonymy is given, and the specimens studied are listed. Among the species of Ocotea in Central America is a group characterized by the presence of an erect indument on the leaves (especially on the lower surface) that is discernible to the touch, with densely to moderately pubescent twigs, tepals that are partially papillose (sometimes only along the margin or near the tip), glabrous or somewhat papillose anthers with the four cells arranged in two superposed pairs and, at least in some species, relatively well-developed staminodia. The term papillose is used here for a dense cover of very short, curly hairs. In a few species the anthers each have a small, sterile tip and the anther cells do not fill the anther completely, as is the case in most species of Ocotea. Although this group is easy to recognize, its taxonomy is confused. The presence of well-developed staminodia has resulted in the inclusion of several species in Phoebe, and later those were transferred to Cinnamomum. Other species have been placed in Nectandra, sharing a common papillosity of the tepals and anthers. Nectandra belizensis (Lundell) Allen resembles in vegetative characters the O. helicterifolia group, but has typical Nectandra stamens (short, broad, with the anther cells arranged in a shallow arc, not in two superposed pairs as in Ocotea). Nectandra belizensis is known from Belize, Costa Rica, and Panama. Rohwer (1991) gave a brief discussion of the group and provided a list of taxa included in it. He also revised the species with the general flower structure of 0. helicterifolia, but which did not have the pubescent leaves and twigs. He noted that the O. helictertfolia group is related to the Ocotea sinuata group, which differs in having tongue-shaped anthers each with a conspicuous sterile tip. In the course of writing a treatment of Ocotea for Flora Mesoamericana, I found several undescribed species in the O. helicterifolia group and several other species that needed to be transferred to Ocotea. A few species of this group occurred outside the area covered by Flora Mesoamericana. In addition to the novelties, I decided it might be useful to publish a key to all species I recognize as belonging to the O. helicterifolia group, as well as new synonyms. In the most recent treatment of Central American Lauraceae (Allen, 1945), most species of the O. helicterifolia group were included in Phoebe, and these species were mostly separated based on leaf size and leaf shape. I found these characters less important than Allen did, and rely more on such characters as inflorescence type (racemose or paniculate-cymose), flower characters (flowers glabrous or pubescent; inner surface of tepals glabrous or pubescent; receptacles glabrous or pubescent inside), and leaf position (alternate or clustered). Use of these characters leads to better-defined species, although some of the species appear quite variable and may be further divided at some later point. Specifically, the Costa Rican specimens of O. helicterifolia seem slightly different and occur at lower altitudes than specimens collected north of Costa Rica. Likewise, specimens of 0. purpurea from Panama seem different (fewer lateral veins, for example) than those from Honduras northward. However, splitting these species can only be done using vegetative characters (leaf shape and size), and because I regard these characters as weak and not reliable, I am reluctant to further divide these rather variable species. In several species the upper rim of the receptacle carries a ring of hairs. These hairs are easily visible and may suggest the receptacle itself is pubescent or the tepals are pubescent on the inner surface. It is necessary to split a receptacle open in order to ascertain whether the receptacle is puNovoN 9: 571-583. 1999. This content downloaded from 157.55.39.103 on Tue, 27 Jun 2017 17:57:07 UTC All use subject to http://about.jstor.org/terms