Fertile complexes (individual reproductive units of ovulate cones) of three Prumnopitys species and Afrocarpus falcatus (Podocarpaceae) were subjected to histological examination and non-destructive NMR imaging. The latter technique allowed the display, frame-by-frame analysis and electronic 'dissection' of internal structures such as the number and courses of vascular traces and resin canals and their morphology. Characters of these internal structures distinguished all three Prumnopitys species from each other and thus were shown to be taxonomically diagnostic. Fertile complexes of Prumnopitys andina and P. taxifolia were most similar, possessing simple vascular traces and few unbranched resin canals. Those of P. ferruginea were very different and possessed an interconnected network of resin ducts within the sarcotesta. These findings are congruent with relationships inferred from molecular phylogenetic studies, in which two subclades were recovered within Prumnopitys. The anatomy of the female fertile complexes of Afrocarpus falcatus was very distinct from all Prumnopitys species analysed. Its most distinctive feature was the existence of a complex network of radial vascular strands originating from within the outer layers of the sarcotesta and penetrating the inner layers of the fertile complex. The surface texture and morphology of the sclerotesta of the seed was also unique to each species. (C) 2004 The Linnean Society of London.

Nuclear magnetic resonance (NMR) imaging was investigated as a tool for the detailed morphological comparison of two species of Podocarpaceae of taxonomic interest; these were difficult to investigate by conventional methods.Two- and three-dimensional NMR images of female cones of Afrocarpus falcatus and Prumnopitys ferruginea were acquired using a range of protocols. Conventional sectioning and microscopic techniques and low-temperature scanning electron microscopy were used where possible, to corroborate the assignments of the NMR images.A three-dimensional network of resin canals in Prumnopitys ferruginea was revealed and the presence of resin confirmed by chemical shift imaging. Similar canals in cones of Afrocarpus falcatus did not contain resin but the presence of spoke-like vascular traces passing through the sclerotesta was demonstrated. marked differences in the structure of the sarcotesta of the two species were readily discernible.NMR imaging allowed noninvasive retrieval of both internal morphological and histochemical information from single specimens in their natural state in a much shorter time than conventional methods would allow and provides useful data for taxonomic purposes in the Podocarpaceae.

Many taxonomic distinctions are made or refined on the basis of herbarium material that is either dried or preserved in spirit medium. Hitherto, examination of internal structure has only been possible by the destructive sectioning of the preserved material. In this paper, the use of nuclear magnetic resonance (NMR) imaging for the non-destructive, non-invasive, complete three-dimensional structural examination of herbarium material is demonstrated for the first time. The experimental materials were the fruiting structures of two species of Southern Hemisphere Podocarpaceae: Acmopyle pancheri and Podocarpus nivalis. Material dried in accordance with standard herbarium techniques was used, as well as material preserved in spirit and freshly gathered fruits. The dried material was subsequently rehydrated using standard techniques, and protocols established for the specimens. Appropriate selection of NMR imaging parameters allowed a variety of anatomical features to be highlighted on a single specimen. Fresh specimens from living material gave the best NMR signals. Dry specimens gave no signal except from the lipid in the seed, but when rehydrated the images yielded almost as much information about internal structure as did a fresh specimen of the same taxon. Thus, NMR imaging has great potential value as a non-invasive method for obtaining details of the internal structure of fruits and seeds and is particularly useful when, as in the case of Acmopyle, the sclerotesta of the seed is too lignified for sectioning by conventional methods.

The developmental morphology and anatomy of the female cones of Acmopyle pancheri (Brongn. & Gris) Pilg. (Podocarpaceae) are described and illustrated, based on observations. histology, scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) imaging. Ovulate development is typically podocarpaceous. Ovules are unitegmic, and horizontal or inclined upwards throughout ontogeny: the pollination drop is inverted because of the declinate micropyle. Ontogeny of the epimatium-ovule complex is acropetal, the epimatium developing first. A terminal, distal sterile bract creates a pollen-scavenging area. During development, the whole cone re-orientates through some 270 degrees, and the seed realigns approx. 60 degrees with respect to the receptacle axis. The 'receptacle' or podocarpium supporting the seed is Termed by gradual fusion of initially free bracts. The structures adnate to these bracts represent homologues of ovuliferous scales; they bear vestigial epimatia which may develop into supernumerary ovules or non-functional epimatia. Thus, female cones of A. pancheri are vestigially multi-ovulate. NMR imaging effectively and non-invasively revealed the three-dimensional arrangement of vascular bundles and resin canals in the cones. (C) 2001 Annals of Botany Company.

The pollination mechanisms of Acmopyle pancheri (Brongn. & Gris) Pilg, and Phyllocladus hypophyllus Hook.f. were investigated by conventional microscopical techniques and by nuclear magnetic resonance (NMR) imaging. Dissimilarities include the orientation of the ovule and type of pollen; Phyllocladus has erect ovules and wettable pollen with vestigial sacci, whereas Acmopyle has more-or-less erect ovules and non-wettable, functionally saccate pollen. Similarities include the mode of formation of the pollination drop and its response upon pollination. In both genera, pollination triggers pollination drop retraction and drop secretion ceases. Neither NMR imaging nor conventional histology of Phyllocladus ovules revealed any specific tissue beneath the ovule which could be responsible for pollination drop retraction. It is more likely, therefore, that the drop is channelled into the vascular supply or the apoplast. These findings invalidate the taxonomic value of the pollination mechanism as a suite of characters traditionally used to separate Phyllocladaceae from Podocarpaceae. (C) 2000 Annals of Botany Company.