Question: Which genus has more species, Bursera or Ipomoea?
Context: Ipomoea obscura, the obscure morning glory or small white morning glory, is a species of the genus "Ipomoea".  It is native to parts of Africa, Asia, and certain Pacific Islands, and it is present in other areas as an introduced species Ipomoea simplex is a central and eastern Southern African grassland species of Convolvulaceae or Sweet Potato family, notable for its large tuber or root, often eaten raw by Xhosa and Sotho herd boys.  Carl Peter Thunberg first described this species in the "Prodromus Plantarum Capensium" of 1794.  'Ipomoea' = 'worm-like', in reference to the twining habit of the genus. Ipomoea alba, sometimes called the tropical white morning-glory or moonflower (but not to be confused with the other species also called moonflower) or moon vine, is a species of night-blooming morning glory, native to tropical and subtropical regions of the New World, from northern Argentina north to Mexico and Florida.  Though formerly classified as genus "Calonyction", species "aculeatum", it is now properly assigned to genus "Ipomoea", subgenus "Quamoclit", section "Calonyction". Bursera fagaroides is a species of flowering plant in the genus "Bursera" known by the common names torchwood copal and fragrant bursera.  It is widespread across much of Mexico from Sonora to Oaxaca, and its range extends just into Arizona in the United States, although some sources suggest that it may now be extirpated in Arizona. Ipomoea amnicola is a species in the genus "Ipomoea".  It is commonly called redcenter morning-glory.  It is found in Mexico, much of South America and has been successfully introduced in the US states of Arkansas, Missouri and Texas. Ipomoea ( ) is the largest genus in the flowering plant family Convolvulaceae, with over 500 species.  It is a large and diverse group with common names including morning glory, water convolvulus or kangkung, sweet potato, bindweed, moonflower, etc. Ipomoea lacunosa, the whitestar, white morning-glory or pitted morningglory, is a species that belongs to the "Ipomoea" genus.  In this genus most members are commonly referred to as "morning glories".  The name for the genus, "Ipomoea", has root in the Greek words "ips" and "homoios", which translates to worm-like.  This is a reference to the plant's vine-like growth.  "Lacunosa" comes from a Latin word meaning air spaces, correlating with the veination of the leaves.  "Ipomoea lacunosa" is native to the United States and grows annually.  The flowers of this species are usually white and smaller than most other morning glories. "Bursera microphylla" is a North American species of tree in the Frankincense Family in the soapwood order.  Bursera microphylla, known by the common name elephant tree in English or 'torote' in Spanish, is a tree in genus "Bursera".  It grows into a distinctive sculptural form, with a thickened, water-storing or caudiciform trunk.  It is found in the southwestern United States and northwestern Mexico. Ipomoea oenotherae is a species of plant of the morning glory ("Ipomoea") genus in the family Convolvulaceae.  It derives its name from the resemblance it bears to plants in the genus "Oenothera".  "Ipomoea oenotherae" is a succulent and a cryptophyte. Bursera, named after the Danish botanist Joachim Burser (1583-1639), is a genus with about 100 described species of flowering shrubs and trees varying in size up to 25 m high.  They are native (often for many species endemic) to the Americas, from the southern United States south through to northern Argentina, in tropical and warm temperate forest habitats.
Answer: Ipomoea