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Plant Biology

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Taxonomy

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Systematic Anatomy Of Euphorbiaceae Subfamily Oldfieldioideae I. Overview, W. John Hayden Jan 1994

Systematic Anatomy Of Euphorbiaceae Subfamily Oldfieldioideae I. Overview, W. John Hayden

Biology Faculty Publications

The biovulate subfamily Oldfieldioideae of Euphorbiaceae, characterized by spiny pollen, is an otherwise apparently diverse assemblage of mostly Southern Hemisphere trees and shrubs that traditionally have been allied with genera of Phyllanthoideae and Porantheroideae sensu Pax and Hoffmann. Although fairly diverse anatomically, the following structures characterize the subfamily with only a few exceptions: pinnate brochidodromous venation with generally randomly organized tertiary and higher order venation; foliar and petiolar glands absent; unicellular or unbranched uniseriate trichomes; latex absent; mucilaginous epidermis or hypodermis; brachyparacytic stomata; vessel elements with simple perforation plates and alternate, often very small, intervascular pits; thick-walled nonseptate imperforate tracheary …


Notes On Neotropical Amanoa (Euphorbiaceae), W. John Hayden Oct 1990

Notes On Neotropical Amanoa (Euphorbiaceae), W. John Hayden

Biology Faculty Publications

Lectotypes are designated for Amanoa caribaea Krug & Urban and A. guianensis Aublet; presumed syntypes of the latter taxon are shown to be heterogeneous by inclusion of a previously unrecognized species. Four new species of Amanoa are described: A. congesta from French Guiana and northeastern Brazil; A. gracillima from Manaus, Brazil; A. nanayensis from Amazonian Peru and adjacent Colombia and Brazil; and A. neglecta from French Guiana and Surinam. Amanoa sinuosa is proposed as a new name for the later homonym A. robusta Leal. A key to the 13 neotropical species is presented.


Systematics And Palynology Of Picrodendron Further Evidence For Relationship With The Oldfieldioideae (Euphorbiaceae), W. John Hayden, W. T. Gillis, D. E. Stone, C. R. Broome, G. L. Webster Jan 1984

Systematics And Palynology Of Picrodendron Further Evidence For Relationship With The Oldfieldioideae (Euphorbiaceae), W. John Hayden, W. T. Gillis, D. E. Stone, C. R. Broome, G. L. Webster

Biology Faculty Publications

Although known to botanical science for 285 years, the genus Picrodendron Planchon has been poorly understood for most of this time. The most pervasive problem has been that of discerning familial relationships, and there have been additional difficulties in typifying the generic name (Hayden & Reveal, 1980) and in distinguishing its three nominate species. This paper provides a systematic treatment for Picrodendron and demonstrates its relationships with Euphorbiaceae subfam. Oldfieldioideae Kohler & Webster as evidenced by data on gross morphology, palynology, anatomy, and cytology.


Proposal For The Conservation Of The Generic Name Picrodendron Grisebach (1859) Against Picrodendron Planchon (1846) (Euphorbiaceae), W. John Hayden, James L. Reveal Aug 1980

Proposal For The Conservation Of The Generic Name Picrodendron Grisebach (1859) Against Picrodendron Planchon (1846) (Euphorbiaceae), W. John Hayden, James L. Reveal

Biology Faculty Publications

Petalacte has been in continuous use for this genus of 1-3 species since proposed by D. Don. The only exception was Lessing's misuse of Petalolepis Cassini, from which he excluded the two original Australian species and substituted two from S. Africa. Lessing was not followed by later authors.T he genus was recently revised by Lundgren (in Bot. Notiser 127: 119-124. 1974) and this revision may be consulted for full references.