The Taxonomic Significance of ducts in the corolla lobes of Vernonia (Vernonieae: Asteraceae)
نویسندگان
چکیده
The multiple longitudinal ducts in the corolla lobes found in the closely related genera Vernonia, Vernonanthura and Trepadonia are microscopically studied and illustrated. The lack of such ducts in the two South American species that have until now been retained in Vernonia indicates that they should probably be excluded from the genus.
منابع مشابه
A new genus, Nothovernonia, from tropical Africa (Asteraceae or Compositae, Vernonieae)
Nothovernoniagen. nov., is described as a new genus for the tropical African Vernonia purpurea Sch.Bip. ex Walp. and Vernonia amblyolepis Bak, having cymiform inflorescences, pedunculate heads with differentiated foliiform bracts at the base, apiculate involucral bracts with scarious lateral margins, spiculiferous corolla lobes, and strongly spinose, sublopohate tricolporate pollen with the col...
متن کاملTwo new genera, Hoffmannanthus and Jeffreycia, mostly from East Africa (Erlangeinae, Vernonieae, Asteraceae)
Two genera of Vernonieae subtribe Erlangeinae with Type A pollen, 5-ribbed achenes, and blunt-tipped sweeping hairs on the styles are described as new, Hoffmannanthus with one species and with Vernonia brachycalyx O. Hoffm. as type, and Jeffreycia with five known species, with Vernonia zanzibarensis Less. as type. Vernonia abbotiana O. Hoffm. is neotypified and is an older name for V. brachycalyx.
متن کاملCytotaxonomic studies in six species of Vernonia (Asteraceae: Vernonieae)
In this report, we describe a mitotic analysis (Giemsa technique) of six species of the genus Vernonia sensu Baker (Asteraceae, Vernonieae, section Lepidaploa) in order to assess the validity of maintaining this genus (sensu Baker) or dividing it into several lesser genera (sensu Robinson). Specimens of the seven species were collected in “cerrado” and “campo rupestre” areas in the states of Sã...
متن کاملLettowia, a new genus of Vernonieae from East Africa (Asteraceae)
A new genus, Lettowia H. Rob. & Skvarla is named for the single East African species originally described as Vernonia nyassae Oliv. Its pollen is lophate and triporate, with a perforated tectum restricted to the muri. The new genus is placed near Vernoniastrum in the subtribe Erlangeinae.
متن کاملNine species from Madagascar are moved from Vernonia to Distephanus (Compositae, Vernonieae)
The genus Distephanus is native to Madagascar, the Mauritius, central and southern Africa, Yemen (Socotra Island), and China. The majority of the diversity is found in Madagascar. Here we provide new combinations for nine species of Vernonia that belong in Distephanus, all from Madagascar. All of the species were formerly placed in the large genus Vernonia, now greatly reduced.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 4 شماره
صفحات -
تاریخ انتشار 2016