Chad Husby

Fairchild Tropical Botanic Garden · Department of Horticulture

Isoprene emissions are a key component in biosphere–atmosphere interactions, and the most significant global source is the Amazon rainforest. However, intra- and interannual variations in biological and environmental factors that regulate isoprene emission from Amazonia are not well understood and, thereby, are poorly represented in models. Here, w...

Isoprene is a chemical compound emitted naturally by soil, microorganisms, plants, and animals into the atmosphere. But plants are the largest emission source, and the amount of emission depends on plant species, weather conditions, and environmental conditions, including exposure to environmental stresses such as heat and drought. Isoprene is very...

Clavija domingensis Urb. & Ekman was one of the many Haitian endemics that were described based on collections made by the great Swedish botanist Leonard Ekman between 1924 and 1928. The species is Critically Endangered sensu IUCN (criteria c2a(i); D) and it is currently the focus of conservation initiatives in Jardin Botanique des Cayes (Haiti), J...

Key message Complex protein-containing reproductive secretions are a conserved trait amongst all extant gymnosperms; the pollination drops of most groups include carbohydrate-modifying enzymes and defence proteins. Abstract Pollination drops are aqueous secretions that receive pollen and transport it to the ovule interior in gymnosperms (Coniferal...

Horsetails (Equisetum, Equisetaceae) are one of the oldest groups of vascular plants with a nearly continuous fossil record dating back to the Carboniferous. Only a few studies have addressed relationships among and within the extant members of this fern genus. We here present the first complete phylogenetic analysis of one or more samples of all e...

[This corrects the article DOI: 10.1093/aobpla/plx013.][This corrects the article DOI: 10.1093/aobpla/plx013.].

Selective pressures acting on plant life histories can drive extreme specialization. One example of such specialization is the evolution of dioecious breeding systems. Evolutionary and ecological theory posits that dioecy may subject male and female individuals to different selective pressures and result in unique sex-mediated adaptive traits relat...

Palms (Arecaceae) are perhaps the most important tropical plant family for human use, both for utility and ornamental horticulture. The wide diversity of palm species with different seed germination characteristics necessitates tailoring horticultural practices to the needs of each. This is crucial for production and conservation horticulture. In t...

The Cycadales are a group of significant global conservation concern and have the highest extinction risk of all seed plants. Understanding the synchronisation of reproductive phenology of Cycadales may be useful for conservation by enabling the targeting of pollen and seed collection from wild populations and identifying the window of fertilisatio...

Editor: Félix Forest Premise of research. Conservation of plant species often requires ex situ (off-site) cultivation of living collections. Cycads constitute the most imperiled major group of plants, and ex situ collections are an important part of conservation planning for this group, given seed recalcitrance, difficulties with tissue culture, an...

Premise of research. Conservation of plant species often requires ex situ (off-site) cultivation of living collections. Cycads constitute the most imperiled major group of plants, and ex situ collections are an important part of conservation planning for this group, given seed recalcitrance, difficulties with tissue culture, and ongoing in situ thr...

The color of new vegetative leaf flushes can vary among species of cycads. It is often used as a diagnostic character in taxonomy and is one of the most appreciated features of the group in ornamental horticulture. However, little is understood about the variability of flush color within species and wild populations. This paper discusses variabilit...

As the most basal monilophytes, eusporangiate ferns can provide key insights into the origins of plant physiological adaptations. The genus Equisetum, the most morphologically and physiologically unusual genus of eusporangiate ferns, has a stomatal apparatus that is unique among all plants. Patterns of stomatal diffusive conductance (gw) were measu...

Cycads comprise the most threatened major group of plants on earth and many species require horticultural assistance to ensure their survival. Appropriate container substrate properties, especially relatively high air space content, are crucial to successful cultivation of most cycads from seed. Cycad substrates in common use include substantial po...

Horsetails are unique survivors of a very ancient group of vascular plants, the Sphenophyta, which has a history reaching back to the Upper Devonian. Despite the striking conservatism of Equisetum architecture and anatomy and the small number of species (15) in the modern flora, their ability to thrive under a wide range of conditions is remarkable...

Zamia acuminata has remained an obscure, poorly understood species for over a century due to possibly misinterpreted or erroneous locality data on the unicate sterile type specimen, a very brief protologue description, the misidentification of the plants from El Valle de Antón in Panama as Z. acuminata, and the erroneous determinations of plants of...

Cycad aulacaspis scale [CAS (Aulacaspis yasumatsui)] is a highly destructive pest insect worldwide. CAS feeds on cycad (Cycas sp.) plantings and is also posing a problem for the foliage industry. The use of spent coffee grounds to prevent or control CAS has received increased popularity in the last few years. This study assesses whether the applica...

Palms have been characterized as tolerant of high winds, but that may be a simplified view. The effects of hurricanes on palm collections at Montgomery Botanical Center offered the opportunity to investigate aspects of natural selection for wind tolerance. A major finding is that wind tolerance is correlated with geography - Caribbean palms are mor...

Morphometric analyses are used to test two competing hypotheses of classification for Aiphanes (Arecaceae: Cocoseae) in the Antilles. Three vegetative characters and three characters of the inflorescence were analyzed via one-way analyses of variance followed by a test of pairwise comparisons for the least-squares means. We found a complex pattern...

The relationships among cypress species of the closely related genera Cupressus L., Callitropsis Oerst., and the recently described Hesperocyparis Bartel & R. A. Price were examined using morphological characters. Previous studies did not fully resolve New World and Old World cypresses, the status of Cupressus duclouxiana B. Hickel, Cupressus benth...

Husby Ch. E., Walkowiak R. J., An Introduction to the Genus Equisetum (Horsetail) and the Class Equisetopsida (Sphenopsida) as a whole, IEA Paper 2012

Numerous studies have suggested that Earth’s climate has changed and will continue to change in response to human activities. It is expected that average temperatures will increase, in some places as much as 4 °C, between 1990 and 2040 (IPCC 2007). In addition, precipitation will probably change, becoming drier in some areas and wetter in others. T...

It has been suggested that Botanic Gardens had in the past, and continue to have today, an important role in plant invasions across the globe. Although mistakes were made in the past, it is contended that such historical actions need to be viewed in the context of the time, and the situation is different today. Although most plant introductions hav...

The basic set of adaptations necessary for salinity tolerance in vascular plants remains unknown. Although much has been published on salinity stress, almost all studies deal with spermatophytes. Studies of salinity tolerance in pteridophytes are relatively rare but hold promise for revealing the fundamental adaptations that all salt-tolerant vascu...

Conservation is increasingly central to the botanic garden mission. Living plant collections are important components of conservation. Critical evaluation of living conservation collections with population genetic analysis can directly inform ex situ conservation strategy. Here, we quantify the degree of genetic variation captured through a populat...

Improved propagation methods greatly benefit conservation of rare cycads. Appropriate substrate conditions, especially excellent root aeration, are crucial to successful cultivation of most cycads. Typical cycad substrates include substantial portions of organic materials that will decompose over time, reducing drainage and increasing water retenti...

Consistent abiotic factors can affect directional selection; cyclones are abiotic phenomena with near-discrete geographic limits. The current study investigates selective pressure of cyclones on plants at the species level, testing for possible natural selection. New World Arecaceae (palms) are used as a model system, as plants with monopodial, unb...

Botanical pharmacopoeias are non-random subsets of floras, with some taxonomic groups over- or under-represented. Moerman [Moerman, D.E., 1979. Symbols and selectivity: a statistical analysis of Native American medical ethnobotany, Journal of Ethnopharmacology 1, 111-119] introduced linear regression/residual analysis to examine these patterns. How...

Balanced ranked-set sampling (RSS) offers improved statistical inference in situations where the units to be sampled can be ranked relative to each other prior to formal measurement. Recent work has shown that provided the ranking process is perfect, unbalanced RSS can do even better. In this article, we examine the performance of one unbalanced RS...

Ranked set sampling (RSS) is a sampling approach that leads to improved statistical inference in situations where the units to be sampled can be ranked (either through some subjective judgment or via the use of an auxiliary variable) relative to each other prior to formal measurement. It has the most promise for leading to improved methodology in s...

This study was conducted to determine the effects of temperature on nutrient release patterns of three polymer-coated fertilizers (PCFs), each using a different coating technology: Osmocote Plus 15N-3.93P-9.96K, Polyon 18N-2.62P-9.96K, and Nutricote 18N-2.62P-6.64K. Each fertilizer was placed in a sand-filled column and leached with distilled water...

This study was conducted to determine the effects of temperature on nutrient release patterns of three polymer-coated fertilizers (PCFs), each using a different coating technology: Osmocote Plus 15N-3.93P-9.96K, Polyon 18N-2.62P-9.96K, and Nutricote 18N-2.62P-6.64K. Each fertilizer was placed in a sand-filled column and leached with distilled water...

Use of polymer-coated fertilizers (PCFs) is widespread in the nursery and greenhouse industries. Temperature is the main factor affecting nutrient release from PCFs, yet there are few reports that quantify temperature-induced nutrient release. Since container substrate temperatures can be at least 40 °C during the summer, this research quantified t...

Equisetum giganteum L., a giant horsetail, is one of the largest living members of an ancient group of non-flowering plants with a history extending back 377 million years. Its hollow upright stems grow to over 5 m in height. Equisetum giganteum occupies a wide range of habitats in southern South America. Colonies of this horsetail occupy large are...