Selaginella is the sole genus in the monotypic family Selaginellaceae, the spikemosses or lesser clubmosses, a type of vascular plant.
Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic substance that induces or sustains such a state in its local vicinity in a moderately sealed container. The word desiccation comes from Latin de- 'thoroughly', and siccare 'to dry'.
Pleopeltis polypodioides, also known as the resurrection fern, is a species of creeping, coarse-textured fern native to the Americas and Africa.
Cytorrhysis is the permanent and irreparable damage to the cell wall after the complete collapse of a plant cell due to the loss of internal positive pressure. Positive pressure within a plant cell is required to maintain the upright structure of the cell wall. Desiccation resulting in cellular collapse occurs when the ability of the plant cell to regulate turgor pressure is compromised by environmental stress. Water continues to diffuse out of the cell after the point of zero turgor pressure, where internal cellular pressure is equal to the external atmospheric pressure, has been reached, generating negative pressure within the cell. That negative pressure pulls the center of the cell inward until the cell wall can no longer withstand the strain. The inward pressure causes the majority of the collapse to occur in the central region of the cell, pushing the organelles within the remaining cytoplasm against the cell walls. Unlike in plasmolysis, the plasma membrane maintains its connections with the cell wall both during and after cellular collapse.
Cryptobiosis or anabiosis is a metabolic state in extremophilic organisms in response to adverse environmental conditions such as desiccation, freezing, and oxygen deficiency. In the cryptobiotic state, all measurable metabolic processes stop, preventing reproduction, development, and repair. When environmental conditions return to being hospitable, the organism will return to its metabolic state of life as it was prior to cryptobiosis.
Selaginella lepidophylla, also known as a resurrection plant, is a species of desert plant in the spikemoss family (Selaginellaceae). It is native to the Chihuahuan Desert of the United States and Mexico. S. lepidophylla is renowned for its ability to survive almost complete desiccation. Resurrection plants are vascular rooted plants capable of surviving extreme desiccation, then resuming normal metabolic activity upon rehydration. The plant's hydro-responsive movements are governed by stem moisture content, tissue properties and a graded distribution of lignified cells affecting concentric stem stiffness and spiraling. During dry weather in its native habitat, its stems curl into a tight ball, uncurling only when exposed to moisture.
Poikilohydry is the lack of ability to maintain and/or regulate water content to achieve homeostasis of cells and tissue connected with quick equilibration of cell/tissue water content to that of the environment. The term is derived from Ancient Greek ποικίλος.
A xerophyte is a species of plant that has adaptations to survive in an environment with little liquid water. Examples of xerophytes include cacti, pineapple and some gymnosperm plants. The morphology and physiology of xerophytes are adapted to conserve water during dry periods. Some species called resurrection plants can survive long periods of extreme dryness or desiccation of their tissues, during which their metabolic activity may effectively shut down. Plants with such morphological and physiological adaptations are said to be xeromorphic. Xerophytes such as cacti are capable of withstanding extended periods of dry conditions as they have deep-spreading roots and capacity to store water. Their waxy, thorny leaves prevent loss of moisture.
Osmoprotectants or compatible solutes are small organic molecules with neutral charge and low toxicity at high concentrations that act as osmolytes and help organisms survive extreme osmotic stress. Osmoprotectants can be placed in three chemical classes: betaines and associated molecules, sugars and polyols, and amino acids. These molecules accumulate in cells and balance the osmotic difference between the cell's surroundings and the cytosol. In plants, their accumulation can increase survival during stresses such as drought. In extreme cases, such as in bdelloid rotifers, tardigrades, brine shrimp, and nematodes, these molecules can allow cells to survive being completely dried out and let them enter a state of suspended animation called cryptobiosis.
Myrothamnus flabellifolius is a plant species in the family Myrothamnaceae native to central and southern Africa. It is also called the resurrection plant for the appearance of dead leaves reviving during rain.
Eragrostis curvula is a species of grass known by the common name weeping lovegrass. Other common names include Boer lovegrass, curved lovegrass, Catalina lovegrass, and African lovegrass.
Jill Farrant, professor of molecular and cell biology at the University of Cape Town, South Africa, is a leading expert on resurrection plants, which 'come back to life' from a desiccated, seemingly dead state when they are rehydrated.
Xerophyta is a genus of flowering plants in the family Velloziaceae. It was named in 1789 by de Jussieu. It is native to Africa, Madagascar, and the Arabian Peninsula.
Haberlea is a monotypic genus of flowering plants in the family Gesneriaceae. The only member of this genus, Haberlea rhodopensis, is endemic to parts of Bulgaria and a small part of northern Greece, especially in the Rhodope Mountains. Common names include Orpheus flower and resurrection plant because of the remarkable ability of Haberlea to survive very long periods of desiccation.
Xerophyta retinervis is a deciduous perennial up to 2 metres tall with stout, erect stems, densely covered in persistent, fibrous leaf bases, often charred and blackened by veldfires. Fragrant flowers appear after fire or rain, and are blue or mauve, or rarely white. The small capsules are covered in rough hairs and are loculicidally dehiscent, releasing numerous small, black angled seeds about 2 mm long. The species is tolerant of extreme conditions such as drought, fire, and low temperatures. The old leaf bases are arranged so that rainwater is funnelled down and to the core, where it is absorbed by densely packed roots that run the entire length of the stem. Strap-shaped leaves occur in tufts along stems.
Boea is a genus of plants in the family Gesneriaceae, with species originating from Australia, China, India, Malaysia, Myanmar, Philippines, Polynesia, Solomon Islands, Thailand, Papua New Guinea, Indonesia, Nepal, Bhutan, Cambodia, Vietnam and Laos.
Craterostigma plantagineum, is a resurrection plant species in the genus Craterostigma. It is a dwarf growing plant and can be found to make a 'carpet' across the ground, with blooms in shades of blue and purple. It is a well-studied desiccation-tolerant species known for its extreme vegetative tolerance against dehydration and desiccation. It is native to parts of Africa and to India. It is known as a resurrection plant.
Dorcoceras is a genus of flowering plants in the African violet family Gesneriaceae, native to Assam, Southeast Asia, China and central Malesia. Its species were transferred from the genus Boea in 2016.
Plant cryopreservation is a genetic resource conservation strategy that allows plant material, such as seeds, pollen, shoot tips or dormant buds to be stored indefinitely in liquid nitrogen. After thawing, these genetic resources can be regenerated into plants and used on the field. While this cryopreservation conservation strategy can be used on all plants, it is often only used under certain circumstances: 1) crops with recalcitrant seeds e.g. avocado, coconut 2) seedless crops such as cultivated banana and plantains or 3) crops that are clonally propagated such as cassava, potato, garlic and sweet potato.
Syntrichia caninervis, also known as steppe screw moss, is a desert moss species distributed throughout the world. As an extremophile, it is able to withstand desiccation under dry conditions with little access to water and is commonly found in hypolithic communities. It makes use of a novel adaptation to the desert environment to harvest and collect water sources such as dew, fog, snow, and rain, using tiny hairs instead of roots. In laboratory experiments, S. caninervis has shown the ability to survive in a simulated Martian environment.
