Acclimatization trials of the two tropical species Solanum sessiliflorum (cocona) and Solanum stramonifolium (coconilla) from Amazonas Venezuela, were carried out at the Botanical Garden of Padua. S. sessiliflorum exhibited a greater difference between the Botanical Garden and the native environment. Plant growth was reduced and pollination was difficult; despite numerous blooms few fruits were produced. Moreover, some fruit abscised early and the persistent ones were still unripe at the end of the season. On the contrary, S. stramonifolium showed good adaptation to the new environmental conditions. The plants grew well and produced a lot of ripe berries. Self-pollination as well as cross-pollination by bumblebees (Bombus terrestris) and other insects present in the open air succeeded. Thus, this latter species could be regarded as potentially exploitable in temperate climates as well as in Venezuela.

A field study to survey the custom of tying rags on sacred trees in the northern part of Israel was carried out during 2000–2001. It included 60 interviewees: 24 Druze, 18 Moslem Arabs, 12 Moslem Bedouins and 6 Christian Arab individuals. Tree veneration was found to be quite uncommon among the Bedouins and rare among the Christian Arabs.

The results of the present study suggest there are 17 reasons for tying rags on sacred trees. Five reasons, as far as the author is aware, were not previously reported from the literature (i.e., breaking an oath, marking a blessed tree, marking the road to a blessed tree, asking for permission to pick fruit, and setting out rags for needy people). These usages appear to be endemic to Israel and to the Druze.

Two customs previously reported from Israel but not corroborated by the present survey are to pacify a tree’s spirit and as a charm for new clothes. Three of the 17 known reasons for tying rags on sacred trees are also known from regions beyond the Middle East (i.e., to transfer illness to the tree, to use a rag as a visiting card, and to pacify the tree’s spirits). And lastly, several customs never reported before from Israel appear to stem from the belief in ancient pagan polytheistic religions (to ensure a good yield, offerings to a tree’s deities/spirits, to pacify the ancestor’s spirits, to commemorate a death, and to pacify a tree’s spirit while picking fruits).

Twelve of the reported 17 reasons for hanging rags on sacred trees are known from Israel. These findings elucidate the widespread and variable tree worship traditions that are prevalent today in the region. In spite of a monotheistic ban against ancient pagan beliefs, trees still remain a subject of worship in Israel today, as manifested by the daily tying of rags upon branches.

Some evidence of the existence of an ancient pharmacological theory—the Doctrine of Signatures—has been found in the folk medicine of Israel. The research reported 14 plants with folk medicinal uses based on the Doctrine of Signatures categories including: similarity of the plant or plant organ to the damaged human organ (Alhagi maurorum, camel thorn; Astragalus macrocarpus, milk-vetch; and Cynoglossum creticum, blue hound’s tongue), similarity to animal shape or behavior (Heliotropium europaeum, European tumsole; Asteriscus spinosus, starwort; and Briza maxima, large quaking grass), similarity of plant color to the color of the disease’s symptoms or the medical phenomena (Rhamnus alaternus, Italian buckthorn; Citrullus colocynthis, bitter gourd; and Ecballium elaterium, squirting cucumber), and similarity of plant habitat or characteristic to human features (Parietaria judaica, wall pellitory; and Ruta chalepensis, African rue).

Archaeological studies of plant remains have indicated that an increase in seed size is frequently correlated with both intensive cultivation and domestication of seed crop plants. To test if starch granules of domesticated root crops are significantly larger than those of wild or less intensively cultivated plants, archaeological and modern specimens of manioc and sweet potato were sampled for starch granules, and granule size was compared across a temporal sequence. The results indicate that a gross generalization can be made that modern specimens of both manioc and sweet potato yield larger starch granules than some archaeological specimens. It does appear, however, that modern domesticated manioc roots produce significantly larger-sized starch granules than those of its purported wild ancestor. Additionally, there exist two lines of evidence that the coastal Peruvian and lowland Neotropical regional types of manioc differ from one another and have been separate for several millennia. These findings indicate that manioc may have been domesticated more than once.

Chaya (Cnidoscolus aconitifolius ssp. aconitifolius Breckon) is a domesticated leafy green vegetable of the Maya region of Guatemala, Belize, southeast Mexico and the Yucatán Peninsula, and parts of Honduras. Though relatively unknown outside of this area, evidence suggests that chaya was of significant importance to ancient peoples of the Yucatán Peninsula and perhaps elsewhere within the Maya region. Here we review what little research has been done on this impressive plant, as well as recount our own ethnobotanical investigation into its use as a food plant and medicine, and discuss its botany, nomenclature, and agricultural use. Due to its ease of cultivation, potential productivity, and above all its substantial nutritional value, we propose chaya as a potential crop for areas outside Mesoamerica.

Cassava is clonally propagated, but Amerindian farmers also use plants from volunteer seedlings to prepare stem cuttings. Although sexual reproduction plays a role in cassava’s evolution it is poorly studied. We examined one aspect of cassava reproductive ecology, seed dormancy and germination. Volunteer seedlings emerge from a soil bank of seeds produced during the previous cycle of cultivation that remain ungerminated through the fallow period, then germinate synchronously after vegetation is slashed and burned. Laboratory experiments showed that germination can be enhanced by mechanical scarification and also by dry heat treatment, suggesting that burning after field clearing could help break dormancy. Germination was also stimulated by high temperatures (35°C) that in nature indicate bare soils, and inhibited by temperatures (25°C) close to those in soil shaded by vegetation and by light. Seeds of both wild and domesticated cassava exhibit physiological dormancy, an adaptation for germination in periodically disturbed habitats. In addition to these preadaptations, preliminary results also suggest specific adaptations of domesticated cassava to the distinctive disturbance regimes of swidden agriculture.

This paper presents the results of a survey on the ethnobotany of the wild Mexican Cucurbitaceae. The sources of information were fieldwork in different regions of Mexico, as well as herbarium specimens and bibliographic references. A total of 34 wild species (26.5% of the 128 wild mexican species) of Cucurbitaceae are reported as used in 24 of the 32 states of Mexico. All of the species are called by one or more local names, and 23 are known by names in native languages. The uses comprise 12 categories, including human medicine (18), food (13), soap substitute (12), fodder (4), toy (3), drink (2), ornate (2), insecticide (1), animal medicine (1), handicrafts (2), container (1), and ceremonial (1), and some uses date back to pre-Hispanic and colonial times.