Papers by Robert L Dressler
Botanical Journal of the Linnean Society, Oct 1, 1993
The anatomy of leaf, stem and root of plants in the orchid subfamily Spiranthoideae was studied a... more The anatomy of leaf, stem and root of plants in the orchid subfamily Spiranthoideae was studied and described from the viewpoint of systematics. Plants were available from most of the geographic range. Tribes Diceratosteleae and Tropidieae show sinuous anticlinal epidermal cell walls in leaves, glandular foliar hairs, tetracytic para-mesoperigenous stomata, unitary tracheary components in the foliar midrib, foliar and cauline stegmata and sclerenchyma, typical cruciate starch grains, thick-walled exodermal, endodermal, and pericyclic cells, and conductive strands of the root embedded in sclerenchyma. The tribe Cranichideae shows straight to curvilinear anticlinal epidermal cell walls in leaves, lack glandular foliar hairs, have variably patterned mesoperigenous stomata, lack sclerenchyma throughout the parts studied, have a binary tracheary component in the foliar midrib, store starch in specialized amyloplasts (spiranthosomes), lack stegmata, have thin-walled exodermal, endodermal, and pericyclic cells, show scalariform thickenings in exodermal cells, and have conductive strands of the root embedded in parenchyma. In Cryptostylis the tracheary component of the foliar midrib is unitary, stomata lack subsidiary cells, starch grains are of the typical cruciate configuration, and passage cells of the endodermis are apparently associated with tilosomes. Anatomical data, when analysed cladistically, support the hypothesis that Spiranthoideae, as currently delimited, are polyphyletic. Corymborkis, Tropidia, and Diceratostele are more closely related to Palmorchis, a likely representative of a basal clade within subfamily Epidendroideae, than to genera of Cranichideae. Likewise, members of Cranichideae are more closely related to Diuris , a representative of subfamily Orchidoideae-tribe Diurideae, than to Corymborkis, Tropidia and Diceratostele. The Corymborkis-Tropidia-Diceratostele -basal epidendroid (Palmorchis) clade may be diagnosed by the foliar synapomorphies of sinuous anticlinal walls of epidermal cells and presence of glandular hairs. The Cranichideae-orchidoid (Diuris) clade may be diagnosed by its variably patterned, mesoperigenous stomata, lack of vascular bundle sclerenchyma, absence of stegmata, unthickened endodermal cell walls in roots, and conductive cells of roots embedded in parenchyma. Relationships within this clade are quite unresolved, when only anatomical data are employed; however all studied genera of Cranichideae, except Cryptostylis, posess a binary tracheary component in the foliar midrib. Cranichideae, excluding Cryptostylis, may be considered monophyletic. All Cranichideae, except Hetaeria and Cryptostylis , possess spirathosomes. Hetaeria may be a basal member within Cranichideae. We consider the phylogenetic position of Crptostylis , in relation to Cranichideae vs. Diurideae, to be equivocal.
Orquideología, Mar 8, 2017
son ilustradas en una Lámina de Disección Compuesta Lankester (LCDP, por sus siglas en inglés) a ... more son ilustradas en una Lámina de Disección Compuesta Lankester (LCDP, por sus siglas en inglés) a partir de material vivo. Tanto científicos como aficionados han confundido estas populares especies Mesoamericanas por muchos años.
Boletin De La Sociedad Botanica De Mexico, 1975
Taxon, 1982
... Other names, such as Coppensia Dumort., or Xeilyathum Raf., have been quite unused. ... 1973;... more ... Other names, such as Coppensia Dumort., or Xeilyathum Raf., have been quite unused. ... 1973; Kachroo et al., Fl. Ladakh 60. 1977, and others). However, the generic name is antedated by Torularia Bonnemaison (1828) as pointed out by RC Rollins in Farr et al., Ind. Nom. Gen. ...
... The Luers in the habitat of Acrorchis ... Monteverde Reserve, EI Valle trail, near continenta... more ... The Luers in the habitat of Acrorchis ... Monteverde Reserve, EI Valle trail, near continental divide with Atlantic ex-posure, lower montane rainforest 10° 20' N, 84° 50' W, 1600 m; 26 Oct 1985; epiphyte on trunk in forest, flower white with purple section; WA Haber ex Eric Bello 3165 ...
Orquideología, May 2, 2017
Taxon, 1966
... The distinction drawn by Lindley between Broughtonia and Lae-liopsis was based on a morpholog... more ... The distinction drawn by Lindley between Broughtonia and Lae-liopsis was based on a morphological miscon-ception (the "external, adnate spur" of Broughtonia), and has proven to be quite untenable when the plants of extreme wes-tern Jamaica are considered. ...
A new species in the genus Daiotyla, Daiotyla xanthina is described a dn illustrated from Colombi... more A new species in the genus Daiotyla, Daiotyla xanthina is described a dn illustrated from Colombia. Among the species of Daiotyla , D. xanthina is eadily distinguished by its yellow, concolorous flowers and the ovate-acute lip, unique in the genus
Sobralia blancoi and S. pendula are both close allies of S. leucoxantha. We also describe S. aspe... more Sobralia blancoi and S. pendula are both close allies of S. leucoxantha. We also describe S. aspera, a species that appears to be more distantly allied.
... Monte Pascoal, Bahia, 8 Nov. 1968, Dressler 1264 (Dressler coll.); 2 males, Itabuna, 3 June 1... more ... Monte Pascoal, Bahia, 8 Nov. 1968, Dressler 1264 (Dressler coll.); 2 males, Itabuna, 3 June 1971, H. Kennedy (Dressler coll.); 2 males, El Altar, Lara, Vene zuela, 19 May 1968, S. Tillett (Dressler coll.); 1 male, El Altar, 16 Aug. ... 197 1 , H. Kennedy (Dressler colI.). ...
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Papers by Robert L Dressler