Question: Are Nymphaea and Acaena both types of hardy plants?

Context articles: Hawaiian tropical high shrublands
Acaena
Hardiness (plants)
Charles Maries
Nymphaea candida
Nymphaea
Pioneer species
Nymphaea thermarum
Gull Rock, Madison
Walking fern

The Hawaiian tropical high shrublands are a tropical savanna ecoregion in the Hawaiian Islands.
 They cover an area of 1900 km2 on the upper slopes of the volcanoes Mauna Kea, Mauna Loa, Hualālai, and Haleakalā.
 They include open shrublands, grasslands, and deserts. Shrubland species include ʻ āheahea ("Chenopodium oahuense"), ʻ ōhelo ʻ ai ("Vaccinium reticulatum"), naʻ enaʻ e ("Dubautia menziesii"), and ʻ iliahi ("Santalum haleakalae").
 Alpine grasslands are dominated by tussock grasses, such as "Deschampsia nubigena", "Eragrostis atropioides", "Panicum tenuifolium", and pili uka ("Trisetum glomeratum").
 Deserts occur on the coldest and driest peaks, where only extremely hardy plants such as ʻ āhinahina ("Argyroxiphium sandwicense") and "Dubautia" species are able to grow.
 The nēnē ("Branta sandvicensis") is one of the few birds found in alpine shrublands, while ʻ uaʻ u ("Pterodroma sandwichensis") nest in this ecoregion.
Acaena is a genus of about 100 species of mainly evergreen, creeping herbaceous perennial plants and subshrubs in the family Rosaceae, native mainly to the Southern Hemisphere, notably New Zealand, Australia and South America, but with a few species extending into the Northern Hemisphere, north to Hawaii ("A. exigua") and California ("A. pinnatifida").
Hardiness of plants describes their ability to survive adverse growing conditions.
 It is usually limited to discussions of climatic adversity.
 Thus a plant's ability to tolerate cold, heat, drought, flooding, or wind are typically considered measurements of hardiness.
 Hardiness of plants is defined by their native extent's geographic location: longitude, latitude and elevation.
 These attributes are often simplified to a hardiness zone.
 In temperate latitudes, the term most often describes resistance to cold, or "cold-hardiness", and is generally measured by the lowest temperature a plant can withstand.
 Hardiness of a plant is usually divided into two categories: tender, and hardy.
 Some sources also use the erroneous terms "Half-hardy" or "Fully hardy".
 Tender plants are those killed by freezing temperatures, while hardy plants survive freezing—at least down to certain temperatures, depending on the plant.
 "Half-hardy" is a term used sometimes in horticulture to describe bedding plants which are sown in heat in winter or early spring, and planted outside after all danger of frost has passed.
 "Fully hardy" usually refers to plants being classified under the Royal Horticultural Society classifications, and can often cause confusion to those not using this method.
Charles Maries (18 December 1851 – 11 October 1902) was an English botanist and plant collector who was sent by James Veitch & Sons of Chelsea, London to search for new hardy plants in Japan, China and Taiwan between 1877 and 1879; there he discovered over 500 new species, which Veitch introduced to England.
 Amongst his finds, several bear his name, including "Abies mariesii", "Davallia mariesii", "Hydrangea macrophylla" "Mariesii", "Platycodon grandiflorus" "Mariesii" and "Viburnum plicatum" "Mariesii".
Nymphaea candida J. Presl is a species of aquatic perennial herbaceous plants in the genus "Nymphaea" native to quiet freshwater habitats in Eurasia, it is in flower from July to August.
 It is sometimes treated as a subspecies of "N. alba" ("N. alba" L. subsp.
 "candida" (J. Presl) Korsh.)
Nymphaea is a genus of hardy and tender aquatic plants in the family Nymphaeaceae.
 The genus has a cosmopolitan distribution.
 Many species are cultivated as ornamental plants, and many cultivars have been bred.
 Some taxa occur as introduced species where they are not native, and some are weeds. Plants of the genus are known commonly as water lilies.
 The genus name is from the Greek νυμφαια, "nymphaia" and the Latin "nymphaea", which mean "water lily" and were inspired by the nymphs of Greek and Latin mythology.
Pioneer species are hardy species which are the first to colonize previously disrupted or damaged ecosystems, beginning a chain of ecological succession that ultimately leads to a more biodiverse steady-state ecosystem.
 Some lichens grow on rocks without soil, so may be among the first of life forms, and break down the rock into soil for plants.
 Since some uncolonized land may have thin, poor quality soils with few nutrients, pioneer species are often hardy plants with adaptations such as long roots, root nodes containing nitrogen-fixing bacteria, and leaves that employ transpiration.
 Note that they are often photosynthetic plants, as no other source of energy (such as other species) except light energy is often available in the early stages of succession, thus making it less likely for a pioneer species to be non-photosynthetic.
 The plants that are often pioneer species also tend to be wind-pollinated rather than insect-pollinated, as insects are unlikely to be present in the usually barren conditions in which pioneer species grow; however, pioneer species tend to reproduce asexually altogether, as the extreme or barren conditions present make it more favourable to reproduce asexually in order to increase reproductive success rather than invest energy into sexual reproduction.
 Pioneer species will die creating plant litter, and break down as "leaf mold" after some time, making new soil for secondary succession (see below), and nutrients for small fish and aquatic plants in adjacent bodies of water.
Nymphaea thermarum is the world's smallest water lily.
 The pads (leaves) of "N. thermarum" can measure only 1 cm across, less than 10% the width of the next smallest species in the genus "Nymphaea" (though they are more usually about 2 cm or 3 cm ).
 By comparison, the largest water lily has pads that can reach 3 m .
 All wild plants were lost due to destruction of its native habitat, but it was saved from extinction when it was grown from seed at the Royal Botanic Gardens, Kew in 2009.
 In January 2014, a surviving water lily was stolen from the Royal Botanic Gardens.
Gull Rock is a small rock ledge 542 feet (165.2 meters) off the coast of Madison in New Haven County, Connecticut.
 It is 883 square feet (269 square meters) in size and made of glacial granite.
 It was named due to the large numbers of seabirds that rest there.
 Some parts of Gull Rock are covered in hardy plants during the summer months, and invertebrates thrive here.
 The island and its neighbors are occasionally considered to be part of the Thimble Islands, though this is uncommon.
 A steel seawall, now decrepit and unused, runs submerged from Gull Rock to the shore.
Walking fern may refer to two species of fern in the genus "Asplenium" which are occasionally placed in a separate genus "Camptosorus".
 The name "walking fern" derives from the fact that new plantlets grow wherever the arching leaves of the parent touch the ground, creating a walking effect.
 Both have evergreen, undivided, slightly leathery leaves which are triangular and taper to a thin point.
 On the bottom of the leaves, sori, or spore-bearing structures, cluster along the veins.
 These hardy plants can be found in shady spots of limestone ledges and limy forest places.