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The genus Pachycereus is restricted to Guatemala, Mexico, and the SW United States and includes 13 species according to the most recent classification. A phylogenetic analysis was conducted in order to test the monophyly of Pachycereus with respect to other genera of subtribe Pachycereinae. A matrix of 44 structural characters (morphology and anatomy) was scored for 29 taxa, including nine species of the Pachycereinae. Results obtained indicated that the subtribe Pachycereinae can only be monophyletic if two species of Stenocereus (S. aragonii and S. eichlamii) are included in it, based on two seed characters (smooth periclinal wall and finely rough relief). Pachycereus is not monophyletic according to the most recent classification. Pachycereus hollianus and P. lepidanthus lack a differentiated fertile zone, and form a basal group in the subtribe Pachycereinae; they do not belong to the genus Pachycereus. Pachycereus fulviceps is related to the genera Cephalocereus and Neobuxbaumia based on nectar zone type, color of fruit pulp, and prismatic calcium oxalate crystals in the epidermic cells. Pachycereus grandis, P. pectenaboriginum, P. pringlei, P. tepamo, and P. weberi are a monophyletic group, based on the presence of a narrow interareolar groove and flowers with a basally constricted tube. This group of five species comprises the genus Pachycereus sensu stricto.
The objective of this study was to describe a wide spectrum of surface structural and anatomical details of the Chinese brake fern (Pteris vittata) using scanning electron microscopy (SEM). SEM revealed that the epidermal cells of the pinnae were elongated with raised periclinal and sinuous anticlinal walls. The pinnae were hypostomatous with randomly scattered anomocytic stomatal complexes positioned at the same level as the epidermis. Stomates were large and elliptical (27.4 μm × 10.2 μm). Cross sections from the central regions of the rachis and the stipe revealed V- and U-shaped vascular bundles, respectively. In each vascular bundle, the xylem strands were sea-horse shaped (hippocampus). In contrast, the pinnae possessed a triangular vascular bundle with uniform mesophyll organization comprising of homogenous lobed parenchyma cells. The indumentum consisted of trichomes and scales, which formed various types of vestiture. Trichomes were borne only on the pinnae and scales on the rachis and stipe. The roots developed a dense network of long root hairs averaging 244 μm long, and the xylem consisted of tracheids with scalariform pitting. Sori were submarginal; continuous along both margins of the pinna and were covered with a false indusium. The sporangia were oblong with a short thick stalk and the annulus was positioned vertically resulting in transverse dehiscence of the sporangium. The paraphyses were uniseriate, unbranched, septate and found to be intermixed with the sporangia. The exine of the globose spores was adorned with thick reticulum in which the areoles contained round tubercles. This study describes surface features in detail, which is essential to studies examining the issue of whether morphological characteristics are related to arsenic hyperaccumulation in P. vittata.
A summary is presented of all Bolivian species of Cyatheaceae and Dicksoniaceae. In total two species of Dicksoniaceae (Culcita 1 sp., Dicksonia 1 sp.) and 34 species of Cyatheaceae (Sphaeropteris 1 sp., Alsophila 5 spp., Cyathea 26 spp., Cnemidaria 2 spp.) are known. One hybrid in Cyathea is recognized. The endemic Cyathea dintelmannii is newly described, and Cyathea herzogii from Bolivia and Peru is separated from Cyathea caracasana var. boliviana. Both species are illustrated. An artificial key to the Bolivian species of Cyatheaceae is provided.
We review the 11 putative species of the neotropical genus Spirotheca and conclude that only five should be treated as distinct taxa. Of these, three have restricted ranges (S. awadendron, S. mahechae, S. michaeli) and two are more widespread (S. rivieriandS. rosea). We provide keys and descriptions of each of these and publish two new combinations (S. rosea and S. rivieri var. passifloroides).
Govenia rubellilabia, a new terrestrial orchid from Sierra Madre de Chiapas, Mexico, is described and illustrated. Diagnostic characters of this new species are compared with other species of Govenia. Govenia rubellilabia is similar in appearance to G. matudae, but it can be distinguished from this species by a shorter inflorescence with fewer flowers, green-yellowish tepals, a reddish lip lacking spots in the margin of the apex, and by a shorter anther beak.
New geographic records of Eleocharis obtusetrigona from the Galapagos Islands, Guatemala, and El Salvador are reported. A description and illustration of E. obtusetrigona are provided, along with a key to separate it from other Central and South American species of Eleocharis subg. Limnochloa with which it has been frequently confused.
A new species, Alstroemeria paraensis, from Pará, Brazil, is described and illustrated. This species is characterized by its robust floral stem, reduced leaves, congested inflorescence, and maculated inner and outer tepals.
Ophiocaryon barnebyanum from the Serra da Neblina (Venezuelan-Brazilian border) and O. neillii from southern Ecuador are described and illustrated, and their morphological relationships with allied species are discussed. Ophiocaryon barnebyanum is morphologically similar to O. duckei, but it differs by its larger leaves, leaflets, petioles, petiolules, and inflorescences, the higher number of secondary veins, and the ciliate sepals. Ophiocaryon neillii is a small tree related to O. klugii but differs by its smaller leaflets, petiolules and inflorescences, fewer secondary veins, lanceolate-acuminate sepals, and orbicular staminodes. An updated key to the species of Ophiocaryon is provided.
Hasseltia allenii is described as a new species from the Pacific drainage of Costa Rica and Panama. It differs from other species of Hasseltia in its long petioles, ovate leaf shape, and glabrous staminal filaments. Data on its morphology, wood anatomy, pollen, and geographical distribution are presented, and a key is provided to distinguish the new species from other species of Hasseltia and closely related genera. The circumscriptions of two of the other species of Hasseltia are modified, and three lectotypes of Hasseltia are designated.
A new species, Senecio chipauquilensis, from the Meseta de Somuncurá in the province of Rio Negro (Argentina), is described and illustrated. The new species resembles Senecio subpanduratus, but it is clearly different by its sessile basal leaves, strongly auriculate and amplexicaul cauline leaves, and less number of phyllaries in the head, dorsally 1–2 veined.