Question: Which plant is found on more continents, Cortaderia or Thermopsis?

Context paragraphs:
Erodium moschatum: Erodium moschatum is a species of flowering plant in the geranium family known by the common names musk stork's-bill and whitestem filaree.  This is a weedy annual or biennial herb which is native to much of Eurasia and North Africa but can be found on most continents where it is an introduced species.  The young plant starts with a flat rosette of compound leaves, each leaf up to 15 centimeters long with many oval-shaped highly lobed and toothed leaflets along a central vein which is hairy, white, and stemlike.  The plant grows to a maximum of about half a meter in height with plentiful fuzzy green foliage.  The small flowers have five sepals behind five purple or lavender petals, each petal just over a centimeter long.  The filaree fruit has a small, glandular body with a long green style up to 4 centimeters in length.

Thermopsis rhombifolia: Thermopsis rhombifolia, also known as prairie thermopsis, is a flowering plant in the legume family.  It is native to Canada and the United States, where it is found in the Great Plains, with extensions into the lower canyons of the Rocky Mountains.  Its natural habitat is dry grasslands and woodlands.

Holarctic: The Holarctic is the name for the biogeographic realm that encompasses the majority of habitats found throughout the northern continents of the world, combining Wallace's Palearctic zoogeographical region, consisting of North Africa and all of Eurasia (with the exception of the southern Arabian Peninsula, Southeast Asia, and the Indian subcontinent), and the Nearctic zoogeographical region, consisting of North America, north of Mexico.  These regions are further subdivided into a variety of ecoregions.  Many ecosystems, and the animal and plant communities that depend on them, are found across multiple continents in large portions of this realm.  The continuity of these ecosystems results from the shared glacial history of the realm.  The floristic Boreal Kingdom corresponds to the Holarctic realm.

Ludwigia palustris: Ludwigia palustris is a species of flowering plant in the evening primrose family known by the common names marsh seedbox, Hampshire-purslane and water purslane.  Its native distribution is unclear, but includes parts of the Americas; it can be found on most continents and spreads easily to become naturalized.  It is also cultivated as an aquarium plant.  This is an aquatic or semiaquatic perennial herb which grows in moist to wet to flooded areas.  It is sometimes a weed.  The stem is up to half a meter long and spreads to form mats on the mud, rooting at nodes in contact with the substrate, or floats ascending in the water.  The leaves are oppositely arranged and green to red or purple in color.  Solitary flowers appear in leaf axils.  They are made up of tiny green sepals and no petals.  They yield small capsular fruits containing many minute seeds.

Cortaderia: Cortaderia is a genus of South American and Central American plants in the Poaceae grass family.

Thermopsis villosa: Thermopsis villosa, or Aaron's rod, is an herbaceous plant in the legume family.  Its native range is in North America, in the southern Appalachian mountains.  It is found elsewhere as an escape from cultivation.

Cushion plant: A cushion plant is a compact, low growing, mat forming plant that is found in alpine, subalpine, arctic, or subarctic environments around the world.  The term "cushion" is usually applied to woody plants that grow as spreading mats, are limited in height above the ground (a few inches at most), have relatively large and deep tap roots, and have life histories adapted to slow growth in a nutrient poor environment with delayed reproductivity and reproductive cycle adaptations.  The plant form is an example of parallel or convergent evolution with species from many different plant families on different continents converging on the same evolutionary adaptations to endure the harsh environmental conditions.

Austroderia richardii: Austroderia richardii, syn.  "Cortaderia richardii", is a species of flowering plant in the family Poaceae.  The genus "Austroderia" is often called "pampas grass", though this name usually refers to "A. selloana".  "Early pampas-grass" is a more specific name.  The name "tussock grass" may also be found.  The Maori name is "toetoe".

Amorpha fruticosa: Amorpha fruticosa is a species of flowering plant in the legume family (Fabaceae) known by several common names, including desert false indigo, false indigo-bush, and bastard indigobush.  It is found wild in most of the contiguous United States, southeastern Canada, and northern Mexico, but it is probably naturalized in the northeastern and northwestern portion of its current range.  The species is also present as an introduced species in Europe, Asia, and other continents.  It is often cultivated as an ornamental plant, and some wild populations may be descended from garden escapes.

Thermopsis: Thermopsis is a genus of legumes, native to temperate North America and east Asia.  They are herbaceous perennials and are known as goldenbanners or false-lupines.

Supporting paragraphs: Cortaderia Thermopsis
Answer: Thermopsis