Question: Which is cultivated across more continents, Clintonia or Washingtonia? 

Context paragraphs:
Washingtonia: Washingtonia is a genus of palms, native to the southwestern United States (in southern California, southwest Arizona, (Nevada) Texas) and northwest Mexico (in northern Baja California and Sonora).  Both "Washingtonia" species are commonly cultivated across the Southern United States, the Middle East, southern Europe, and north Africa, where they have greatly hybridized.

Continental drift: Continental drift is the movement of the Earth's continents relative to each other, thus appearing to "drift" across the ocean bed.  The speculation that continents might have 'drifted' was first put forward by Abraham Ortelius in 1596.  The concept was independently and more fully developed by Alfred Wegener in 1912, but his theory was rejected by some for lack of a mechanism (though this was supplied later by Arthur Holmes).  The idea of continental drift has been subsumed by the theory of plate tectonics, which explains how the continents move.

Juglans regia: Juglans regia, the Persian walnut, English walnut, or especially in Great Britain, common walnut, is an Old World walnut tree species native to the region stretching from the Balkans eastward to the Himalayas and southwest China.  The largest forests are in Kyrgyzstan, where trees occur in extensive, nearly pure walnut forests at 1,000–2,000 m (3000 to 7000 ft) altitude—notably at Arslanbob in Jalal-Abad Province.  It is widely cultivated across Europe.

Coffee in world cultures: Countries have cultivated coffee beans into various vehicles to satisfy needs unique to each country.  Whether it be for energy, socialization, or tradition, the cultivation of coffee has served as a motivating force of the world.  The modernization of coffee and its unique forms across cultures are markers of tradition and modern changes across continents.  Coffee culture appears in the way in which people consume coffee, the way they make it, and where coffee is served and shared.  Each of these factors combined reflects the lives of the people in these countries and the importance of coffee across the world.

Buchanania lanzan: Buchanania lanzan is a tree which produces the seeds known as charoli (or chironji).  These almond-flavoured seeds are used as a cooking spice primarily in India.  "Buchanania lanzan" is cultivated across India, primarily in the northwest.  After the hard shell is cracked, the stubby seed within is as soft as a pine nut.

Clintonia: Clintonia is a genus of flowering plants first described as a genus in 1818.  It is distributed across North America and eastern Asia where it is found as an understory plant in woodlands.  It was named after De Witt Clinton, an 18th-century botanist and U.S. politician.

Allahabadi Surkha: Allahabadi Surkha are a special category of guava having deep pink color inside instead of the typical white color and an apple red exterior skin.  This fruit is sweet, and strongly flavoured with few seeds and is slightly depressed at both ends.  The plants are vigorous, dome shaped and compact.  These guavas are cultivated across the Allahabad, Uttar Pradesh region in the northern belt of India.  Allahabadi Surkha is cultivated today on almost 1000 hectares of land mainly under Kaushambi and Kaurihar -II districts of Allahabad.  The fruit is known for its medical properties such that during the winter season because it neutralizes disease symptoms.

Economy of the Americas: The economy of the Americas comprises more than 953 million people in 35 different countries and 18 territories.  Sometimes divided into the continents of North America and South America depending on the source, like other continents, the wealth of the states in the Americas varies, although the poorest are well above the poorest states of other continents in terms of GDP and living standards.  The difference in wealth across the Americas can be seen roughly between the economies of North America and South America, with the countries in the former significantly better off than those in the latter.

Bauhinia × blakeana: Bauhinia" × "blakeana commonly called the Hong Kong Orchid Tree is a legume tree of the genus "Bauhinia", with large thick leaves and striking purplish red flowers.  The fragrant, orchid-like flowers are usually 10 to across, and bloom from early November to the end of March.  Although now cultivated in many areas, it originated in Hong Kong in 1880 and apparently all of the cultivated trees derive from one cultivated at the Hong Kong Botanical Gardens and widely planted in Hong Kong starting in 1914.  It is referred to as bauhinia in non-scientific literature though this is the name of the genus.  It is sometimes called the Hong Kong orchid (香港蘭).  In Hong Kong, it is most commonly referred to by its Chinese name of "洋紫荊".

Ginkgo: Ginkgo is a genus of highly unusual non-flowering plants.  The scientific name is also used as the English name.  The order to which it belongs, Ginkgoales, first appeared in the Permian, 270 million years ago, possibly derived from "seed ferns" of the order Peltaspermales.  The rate of evolution within the genus has been slow, and almost all its species had become extinct by the end of the Pliocene; the exception is the sole living species, "Ginkgo biloba", which is only found in the wild in China, but is cultivated across the world.  The relationships between ginkgos and other groups of plants are not fully resolved.

Supporting paragraphs: Clintonia Washingtonia
Answer: Washingtonia