Discrimination of pollen of New Zealand manuka (Leptospermum scoparium agg.) and kanuka (Kunzea spp.) (Myrtaceae).

The very similar appearance of pollen of the New Zealand Myrtaceous taxa Leptospermum scoparium s.l. (manuka) and Kunzea spp. (kanuka) has led palynologists to combine them in paleoecological and melissopalynological studies. This is unfortunate, as differentiation of these taxa would improve understanding of past ecological change and has potential to add value to the New Zealand honey industry, where manuka honey attracts a premium price. Here, we examine in detail the pollen morphology of the 10 Kunzea species and a number of Leptospermum scoparium morphotypes collected from around New Zealand, using light microscopy, SEM, and Classifynder (an automated palynology system). Our results suggest that at a generic level the New Zealand Leptospermum and Kunzea pollen can be readily differentiated, but the differences between pollen from the morphotypes of Leptospermum or between the species of Kunzea are less discernible. While size is a determinant factor-equatorial diameter of Leptospermum scoparium pollen is 19.08 ± 1.28 µm, compared to 16.30 ± 0.95 µm for Kunzea spp.-other criteria such as surface texture and shape characteristics are also diagnostic. A support vector machine set up to differentiate Leptospermum from Kunzea pollen using images captured by the Classifynder system had a prediction accuracy of ~95%. This study is a step towards future melissopalynological differentiation of manuka honey using automated pollen image capture and classification approaches.

Laryngopyocoele presenting with acute airway obstruction.

A 66-year-old woman was transferred to the emergency department with a left-sided neck lump and fever. She was stridulous with reduced consciousness level and required immediate intubation to protect her airway. CT imaging showed a fluid-filled and air-filled lesion in the left side of the neck; the diagnosis was later confirmed as an infected laryngocoele. She underwent ultrasound guided drainage of the lesion with successful reduction of the neck lump. Following elective tracheostomy she was weaned from ventilation. Subsequent direct endoscopy and biopsy showed no evidence of malignancy or other lesion. She was discharged with permanent tracheostomy to be sustained until definitive surgical resection of the laryngocoele.

Indication of global deforestation at the Cretaceous-Tertiary boundary by New Zealand fern spike.

The devastating effect on terrestrial plant communities of a bolide impact at the Cretaceous-Tertiary boundary is shown in fossil pollen and spore assemblages by a diverse flora being abruptly replaced by one dominated by a few species of fern. Well documented in North America, this fern spike signals widespread deforestation due to an impact winter or massive wildfires. A Southern Hemisphere record of a fern spike, together with a large iridium anomaly, indicates that the devastation was truly global. Recovery of New Zealand plant communities followed a pattern consistent with major climatic perturbations occurring after an impact winter that was possibly preceded by global wildfires.