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Acalypheae

About: Acalypheae is a(n) research topic. Over the lifetime, 14 publication(s) have been published within this topic receiving 334 citation(s).

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01 Jan 1962
TL;DR: The morphology of the pollen grains of the Stenolobeae is in agreement with the opinion of PAX, that any separation of these Australian genera is an artificial one.
Abstract: In the present study pollen morphology of the Euphorbeaceae is treated as an additional character in taxonomy. Besides the greater part of the genera occurring in the system of PAX and K. HOFFMANN (1931), most of the genera published after 1931 are studied. The pollen grains have been described with the aid of a terminology as simple as possible. In principle the terminology of IVERSEN and TROELS-SMITH has been followed, although in addition, many improvements of ERDTMAN have been used. One of the simplifications is the rejection of POTONIE’s term sculpture. All elements occurring on the endexine are called structure elements; all structure elements together form the structure of a pollen grain. For the sake of consequence endexine apertures and extexine apertures are discussed separately. Different pollen grains are placed in different pollen types. If the differences are of minor importance, the pollen grains are placed in subtypes. Several types can have some characters in common. To express the correspondences, these types are assembled in configurations. As the pollen types in Phyllanthoideae and Crotonoideae differ distinctly, the division of the Euphorbiaceae in these subfamilies is maintained in the discussion of the results. The Phyllanthodieae can be separated in three large groups of pollen types ( Antidesma configuration, Amanoa configuration and Aristogeitonia configuration), which agrees with the grouping of PAX in 1924. The remaining small configurations belong in taxonomic respect to the genera of the Antidesma configuration. In the Crotonoideae many genera possess pollen grains with a croton-pattern. These genera should be treated as a single group. Besides this natural group, the Plukenetiinae possess pollen grains which are clearly distinguished from other genera in the Crotonoideae. Pollen grains of Omphalea are similar to those in the Plukenetia configuration. This pollen-morphological result agrees with the opinion of CROIZAT. The remaining pollen grains in the Crotonoideae are less easy to differentiate in groups. One of the largest configurations is the Mallotus configuration, which includes most genera of the Acalypheae and several genera or other tribes. The Hippomane configuration is another large one. This configuration comprises the tribes Hippomaneae and Euphorbieae. The pollen grains of both tribes are very similar. The genus Pachystroma is pollen-morphologically as well as taxonomically related to the tribe Hippomaneae. Pera, treated as a separate tribe by PAX and K. HOFFMANN, is related by its pollen grains to some genera in the Acalypheae. Dalechampia is habitually related to the genera in the Plukenetiinae. Pollenmorphological data, however, do not support this relation. The pollen grains of Dalechampia are not similar to any other pollen type. The morphology of the pollen grains of the Stenolobeae is in agreement with the opinion of PAX, that any separation of these Australian genera is an artificial one.

163 citations

Journal ArticleDOI
Abstract: This is the fourth, last and largest installment of a palynological study of the Acalyphoideae that examined in light, scanning electron and transmission electron microscopy, the pollen of a grand total of 460 collections representing 372 species from 112 of the 116 assigned genera. Part 4 describes the pollen of tribe Acalypheae pro parte, subtribes Claoxylinae (Erythrococca, Claoxylon, Claoxylopsis, Mareya, Mareyopsis. Discoclaoxylon, Micrococca, Amyrea), Lobaniliinae (Lobanilia), Rottlerinae (Mallotus, Deuteromallotus, Cordemoya, Cococceras, Trewia, Neotrewia, Rockinghamia, Octospermum), Acalyphinae (Acalypha), Lasiococcinae (Lasiococca, Spathiostemon, Homonoia), tribe Plukenetieae, subtribe Plukenetiinae (Haematostemon, Astrococcus, Angostyles, Romanoa, Eleutherostigma, Plukenetia, Vigia); subtribe Tragiinae (Cnesmone, Megistostigma, Sphaerortylis, Tragiella, Platygyna, Tragia, Acidoton, (Pachystylidium); subtribe Dalechampiinae (Dalechampia) and tribe Omphaleae (Omphalea). None of the above multigeneric tribes or subtribes have uniform morphology or exine structure, but, with the notable exception of Plukenetieae, neither do they have any genera with outstanding palynological distinctions. Most members of Cloaxylinae have pollen of a generalized type. although the data support the separation of Mareyopsis from Mareya. Pollen of Amyrea is distinguished by a striate sculpture. Pollen of Mallotus is uniform and representative of the subtribe Rottlerinae: punctate-microspinulose tecta. thin foot layers, small columellae and thick continuous tecta. Pollen of Acalypha is small, brevicolp(or)ate, and mostly angulaperturate in polar view. One genus of subtribe Lasiococcinae, Spathiostemon, has a supratectal sculpture of lirae with cross striations, while a second, Homonoia, has a tectum. composed of elongate, vertically oriented individual rods with acute tips. The exine structure of the large tribe Plukenetieae is strikingly diverse with most variants unique in the Acalyphoideae if not the family. Pollen of most members of Plukenetiinae is of either the Conophora type (punctate tecta, prominent columellae, and granular area under the tectum) or the Loretensis type (reticulate exines, crenate muri, unremarkable structure). Pollen of subtribe Tragiinae is more diverse than Plukenetiinae. Three Asian genera, Cnesmone, Megistostigma and Pachystylidium, have poorly defined apertures, and reduced exines. Inaperturate pollen is present in Platygyna, two species of Acidoton and Tragia sellowiana, all of which have exines consisting mostly of columellae, Three pollen types are recognized in Tragia: (1) the Ramosa type is three-colpate, intectate, and has exines or large columellae and thick foot layers; (2) the Lukafuensis type is three-colpate and has reticulate exines with arched colpal margins at the equator; (3) the Urens type has poorly defined apertures, is tectate with exines lacking foot layers. Pollen of Tragiella is very similar to the Lukafuensis type of Tragia. The large grains of the monogeneric subtribe Dalechampiinae are characterized by two prominent equatorial bands (costae). In Plukenetieae, the pollen data support: the reduction of three monotypic genera, Eleutherostigma, Romanoa and Vigia to species of Plukenetia: a close relationship among Cnesmone. Megistostigma and Pachystylidium; a congeneric treatment of Platygyna and Acidoton microphyllus and A. urens, or at least the restriction of Acidoton to these two species; separate generic status for Tragia sect. Tragia which has the Ramosa pollen type; a congeneric treatment of Tragiella and those species of Tragia (T sect. Tagira) with the Lukafuensis pollen type; separate tribal status for Dalechampia. Pollen of Omphaleae is three-colpate, has irregular columellae and foot layers, and a non-apertural endexine that, after acetolysis, separates from the ectexine like the aperturate pollen of Crotonoideae. The results of the pollen study of the entire Acalyphoideae are discussed and Parts 1, 2 and 3 are summarized. Of the multigeneric tribes and subtribes, there are significant pollen differences among the taxa of Ampereae, of Chrozophoreae (subtribe Ditaxinae), of Pycnocomeae (subtribe Pycnocominae), and of Adelieae, as well as taxa of Plukenetieae. The nearly identical pollen of Ricininae and Adrianinae would support their treatment as one subtribe. The subtribes Mercurialinae and Dysopsidinae share similar pollen that is sufficiently distinct from the remaining Acalypheae to merit their treatment as one subtribe. Most pollen of Acalyphoideae is three-colporate with a lalongate endoaperture and punctate-microspinulose or punctate sculpture. Most exines consist of thin foot layers, modest columellae and continuous, mostly thick tecta. (C) 2002 Elsevier Science B.V. All rights reserved.

43 citations

Book
01 Jan 1992

37 citations

Journal ArticleDOI
Abstract: This is the third paper of an extensive study of pollen morphology and exine structure of Acalyphoideae (Euphorbiaceae) following the most recent system of Webster Pollen from 120 collections representing 96 species and 30 genera is described and illustrated with light microscopy, scanning and transmission electron microscopy These taxa are from tribes Epiprineae, Adelieae, Alchorneae, and Acalypheae pro parte Pollen of eight genera, Epiprinus, Symphyllia, Adenochlaena, Cleidiocarpon, Koilodepas, Cladogynos, Cephalocrotonopsis and Cephalocroton, of the nine assigned to Epiprinae share 3-colporate apertures, microreticulate, punctate or deeply punctate tecta, well developed or prominent columellae (Koilodepas excepted) and thin foot layers; pollen of the ninth genus, Cephalomappa, has porelike colpi, a coarsely reticulate exine, irregular columellae and an irregular foot layer Of the five genera assigned to Adelieae, pollen of Adelia, Lasiocroton and Leucocroton is similar: 3-colp(oroid)ate with stratified opercula, crotonoid tecta and thin foot layers; grains of Enriquebeltrania and Crotonogynopsis lack opercula and the latter has a distinctive infratectum of poorly differentiated columellae All genera examined of tribe Alchorneae, seven of the nine, have exines with unstratified opercula and elongated columellae near the endoaperture Exines of subtribe Alchorneinae (Orfilea, Alchornea, Coelebogyne, Aparisthmium, Bocquillonia) have complex infratecta of poorly differentiated columellae, whereas pollen of Conceveiba and Gavarretia, the two genera examined of the three assigned to subtribe Conceveibinae, has a single layer of short columellae and almost identical tectal morphology In the large tribe Acalypheae, pollen of the first six of the 11 subtribes was examined Pollen of Ricinus (Ricininae) and Adriana (Adrianinae) share indistinguishable exine structures and tecta Pollen of Mercurialis and Leidesia of subtribe Mercurialinae and pollen of Dysopsis of subtribe Dysopsidinae are almost identical: finely reticulate tecta, very thin apertural endexines, elongate columellae, and channeled/perforate foot layers All three genera of subtribe Cleidiinae have grains that are 3-colporate and have complete tecta; pollen of Wetria has a tectum morphology very similar to that of Ricinus and Adriana; pollen of Cleidion is 3-brevicolporate with microrugulose or punctate tecta, and has threadlike non-apertural endexines and foot layers, and thick tecta; exines of Sampantaea have an endexine throughout the grain, thin foot layers, very short columellae and a thick continuous tectum Pollen of Macaranga of subtribe Macaranginae is small, 3-colporate with poorly defined endoapertures, and an exine structure characterized by thin foot layers, short columellae, and thick tecta Pollen data support: the concept of the subtribe Epiprininae, but indicate that subtribe Cephalomappinae (Cephalomappa) is not related and should be considered for separate tribal status; a close relationship among Adelia, Lasiocroton and Leucocroton, but not with the two remaining members of Adelieae, Enriquebeltrania and Crotonogynopsis, which do not appear to be closely related to each other; the present concept of Alchorneae and subtribes Alchorneinae and Conceveibinae Within the genera examined of the first six subtribes of Acalypheae, the pollen data: support a close relationship between the monogeneric subtribes Ricininae and Adrianinae; indicate a close relationship between subtribes Mercurialinae (Mercurialis, Leidesia) and Dysopsidinae (Dysopsis); suggest that Wetria is not closely related to Cleidion or Sampantaea (Cleidiinae); tentatively support the concept of Macaranginae as comprising only Macaranga

34 citations

Journal ArticleDOI
TL;DR: An early Miocene flora from the Foulden Maar diatomite deposit, Otago, southern New Zealand contains numerous organically-preserved fossil leaf compressions, flowers and fruits that blew or fell into a small enclosed maar lake and must have been derived from trees or shrubs growing around the lake margin.
Abstract: An early Miocene (ca. 23 Ma) flora from the Foulden Maar diatomite deposit, Otago, southern New Zealand contains numerous organically-preserved fossil leaf compressions, flowers and fruits. A fossilised male partial lax inflorescence carrying in situ pollen of the type Nyssapollenites endobalteus (McIntyre) Kemp & Harris is assigned to Euphorbiaceae, subfamily Acalyphoideae, tribe Acalypheae. Leaves from the same site are referred to the Mallotus–Macaranga clade (Euphorbiaceae: Acalyphoideae) on the basis of leaf architecture and epidermal features and described as Malloranga fouldenensis gen. et sp. nov. In addition, euphorbiaceous trilobed capsular fruits are assigned to the form genus Euphorbiotheca as E. mallotoides sp. nov. and an immature infructescence is also described. The inflorescence, pollen, leaves and fruits blew or fell into a small enclosed maar lake and must have been derived from trees or shrubs growing around the lake margin.

27 citations

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No. of papers in the topic in previous years
YearPapers
20121
20101
20082
20021
20001
19971