What does morphology tell us about orchid relationships?—a cladistic analysis

Abstract

A cladistic analysis of Orchidaceae was undertaken for 98 genera using 71 morphological apomorphies based on a reconsideration of previous character analyses and newly discovered variation. The equally weighted analysis found 60 000 most parsimonious trees with low consistency (CI = 0.29) but high retention (RI = 0.83). The strict consensus reveals a significant amount of structure, and most traditionally recognized subfamilies are supported as monophyletic, including the Apostasioideae, Cypripedioideae, Spiranthoideae, and Epidendroideae. Orchidoideae in the broad sense are paraphyletic, giving rise to spiranthoids. Vanilloids are sister to epidendroids, although exhibiting several states otherwise found only in clearly basal groups, such as Apostasioideae. The nonvandoid epidendroids are poorly resolved, due to a high degree of homoplasy. The vandoids appear to be monophyletic, contrary to recent molecular evidence, possibly due to repeated parallel development of the vandoid character suite. The importance of vegetative characters as evidence putatively independent from floral features is demonstrated in the placement of Tropidia. Implied weighting analysis of these data resulted in similar patterns at high levels, although the Orchidoideae and Spiranthoideae may each be monophyletic and the nonvandoid epidendroids are more resolved. The high degree of structure implied in previous orchid classifications must be reconsidered, given the poor resolution at lower levels in the present trees.

Cytogenetics and cytotaxonomy of some Brazilian species of Cymbidioid orchids

“…In the tribe Cymbidieae, there is a higher diversity of chromosome numbers, in agreement with the polyphylie observed on the basis of morphological (Freudenstein and Rasmussen, 1999) and molecular evidence (Cameron et al, 1999). The main haploid numbers are n = 27 and 23 in the subtribe Eulophiinae, n = 21, 20, n = 28, 27 in the subtribe Cyrtopodiinae, n = 20 in a single species of Acriopsidinae, and n = 27 and n = 34 in Catasetinae.…”

“…The only Lockartia species analyzed in the present work exhibited 2n = 56 (Figure 4d), which coincides with the previous reports of Charanasri and Kamemoto (1975) for L. micrantha. These data support the inclusion of Lockartia in Oncidiinae, in opposition to the assumption of Freudenstein and Rasmussen (1999) based on the absence of leaf articulation in this genus.…”

“…This same reasoning is also applied to other primitive and highly polyploid genera of orchids, such as Neuwiedia and Apostasia (Okada, 1988). On the other hand, diploids and recent polyploids exhibit more derived characters in different parallel evolutionary lines, as Dipteranthus in Ornithocephalinae (Williams et al, 1994) and Lockartia in Oncidiinae (Chase, 1986;Freudenstein and Rasmussen, 1999).…”

“…The genus Cymbidium is notable for its constancy in chromosome number (n = 20), except the species of subgenus Jensoa (sensu Christopher and Cribb, 1984), with 2n = 38 (Aoyama and Tanaka, 1988). According to Freudenstein and Rasmussen (1999) Cymbidium is a member of the Vandoid phylad while Jensoa is part of the large epidendroid polytomy, since Jensoa shows later antera bending and lacks other features such as two pollinia or the presence of endocarpic trichomes.…”

Características micromorfológicas e químicas das ceras cuticulares de Cleistes (Orchidaceae, Pogonieae)

“…Vanilloid orchids (i.e., subfamily Vanilloideae; Freudenstein & Rasmussen 1999;Freudenstein et al 2004;Cameron 2004) comprise tribes Vanilleae and Pogo-Collection sites and plant material Leaves were collected from dried specimens for scanning electron microscopy (SEM) study and from natural populations for chemical analyzes. Habitats where Cleistes specimens grow include, among other biomes, "vereda" (wet savannas), "campos de altitude" (high mountain grasslands), "campo limpo" (grasslands) and "campo sujo" (grasslands with shrubs).…”