Question: Which genus is native to North America, Jovibarba or Dirca?
Context: Asaphidion is a Holarctic genus of ground beetle native to Europe, the Near East, North Africa, and North America.  Though predominantly a Palaearctic genus with one adventive exotic species in North America ("A. curtum" ), there are two native North American species in the genus: "A. alaskanum" and "A. yukonense" .  Both native taxa are Arctic in distribution, found mainly in tundra environments.  The introduced "A. curtum" is now found in the northeastern United States and adjacent Canadian maritime provinces.  These large-eyed, diurnal species are fast-running predators believed to be specialists on springtails and other tiny, soft-bodied prey. Agrilus planipennis, commonly known as the emerald ash borer, is a green buprestid or jewel beetle native to northeastern Asia that feeds on ash species.  Females lay eggs in bark crevices on ash trees, and larvae feed underneath the bark of ash trees to emerge as adults in one to two years.  In its native range, it is typically found at low densities and does not cause significant damage to trees native to the area.  Outside its native range, it is an invasive species and is highly destructive to ash trees native to northwest Europe and North America.  Prior to being found in North America, very little was known about emerald ash borer in its native range; this has resulted in much of the research on its biology being focused in North America.  Local governments in North America are attempting to control it by monitoring its spread, diversifying tree species, insecticides, and biological control. Typhonodorum is a monotypic genus of flowering plants in the family Araceae.  The single species making up this genus is Typhonodorum lindleyanum.  The genus is native to Madagascar, the Comores, Zanzibar, and Mauritius.  This genus is believed to be closely related to "Peltandra" even though "Peltandra" is only found in North America and there don't appear to exist closely related genera in the African mainland.  There isn't fossil evidence to link the two genera so it has been proposed that there once was a genus in Africa from which the two genera had originated.  The African mainland genus spread to North America and to Madagascar 50 million years ago before it broke off.  Then the African genus became extinct and the North American and Madagascan genera remained. Dirca is a genus of three or four species of flowering plants in the family Thymelaeaceae, native to North America.  The genus is named after Dirce in Greek mythology.  The general common name for this deciduous shrub is leatherwood; other names include moosewood, ropebark and Powhatan-derived wicopy.  The stems of "Dirca" are exceptionally pliable and the bark is difficult to tear by hand; for this reason, its stems were used by Native Americans in eastern North America as thongs or ropes.  Members of the genus can grow to a maximum height of about three meters, and are often associated with rich, moist woods or slopes above creeks or streams. Cakile is a genus within the flowering plant family Brassicaceae.  Species in this genus are commonly known as searockets, though this name on its own is applied particularly to whatever member of the species is native or most common in the region concerned, the European searocket "Cakile maritima" in Europe, and the American searocket "C. edentula" in North America.  The genus is native to Europe, Asia and North America, but the European searocket has been introduced into North America and has spread widely on both east and west coasts; in many places it is replacing the native "C. edentula", and is regarded as an undesirable invasive species. Eratigena is a genus of spider in the Agelenidae family.  Most of its species were moved from the genus "Tegenaria" in 2013.  Two species that frequently build webs in and around human dwellings are now placed in this genus.  "Eratigena agrestis" is the hobo spider, native to Europe and Central Asia, introduced to North America.  "Eratigena atrica" is the giant house spider, native to Europe and also introduced into North America. Dirca occidentalis, or western leatherwood, is a deciduous shrub with leaves three to seven centimeters in length.  Yellow flowers emerge prior to leafing.  It grows on moist and shaded slopes.  It is rare and endemic to the San Francisco Bay area of California.  Its closest relative, "Dirca palustris", lives in the Eastern half of North America. Jovibarba ("beard of Jupiter") is a small genus of three species of succulent flowering plants in the family Crassulaceae, endemic to mountainous regions in the southeastern quadrant of Europe.  The genus is sometimes classified as a subgenus of "Sempervivum", to which it is closely related.  "Jovibarba" have pale-greenish-yellow or yellow actinomorphic flowers with about six petals, while "Sempervivum" have generally pinkish flowers with around twice as many petals, which open more widely than jovibarba flowers.  The common name hen and chicks is applied to some "Jovibarba" species (and also species in several other genera). Dirca palustris, or eastern leatherwood, is a shrub that grows to a maximum height of about three meters.  It is native to the eastern half of North America but uncommon, found in rich woods, and is occasionally cultivated.  The species name, "palustris", means "of the swamps".  It is often hard to recognize because the flowers, which come out just before leafing, last a very short time and "D. palustris" may be mixed in with the much more frequent Spicebush, which also has small yellow flowers that appear before the leaves and do so at just about the same time in the early spring.  Its closest relative, the western leatherwood, lives across the continent in the San Francisco Bay Area. Jovibarba heuffelii, common name Hen-and-chickens, as a plant species native to the Balkans and to the Carpathians in Europe but reportedly naturalized in Wisconsin and probably in other parts of North America.  It grows on rocky outcrops.
Answer: Dirca