Question: Which genus has more species, Goldenrod or Boykinia?
Context: Solidago lepida , the western Canada goldenrod or western goldenrod, is a North American plant species in the genus "Solidago" of the sunflower family.  It is widespread across much of Canada, the western United States, and northern Mexico. Asteroma is a genus of pathogenic fungus in the family Gnomoniaceae, containing several species that cause leaf spot and canker on plants such as goldenrod, primrose, and "Erythronium". Boykinia aconitifolia, also known as Brook saxifrage and Allegheny brookfoam, is a species of vascular plant in the genus Boykinia.  It is native to the southeastern region of the United States, ranging from West Virginia to Alabama and Georgia.  It grows in wet woodlands, on the edges of ponds and lakes, or in other moist areas, flowering in the summer.  It has both basal and cauline leaves, with petioles three to eighteen centimeters long.  Leaves are generally reniform, but can be orbiculate to cordate with three to seven lobes.  The seeds are black with tubercles. Solidago sempervirens, the seaside goldenrod or salt-marsh goldenrod, is a plant species in the genus "Solidago" of the Asteraceae family.  It is native to eastern North America and parts of the Caribbean.  It is an introduced species in the Great Lakes region and the Azores. Boykinia is a small genus of plants related to the saxifrages.  It contains at least nine species, known as brookfoams.  Brookfoams are glandular rhizomatous creeping perennials with highly lobed or toothed leaves and inflorescences of petite flowers.  They are native to North America and Asia. The goldenrod gall fly ("Eurosta solidaginis"), also known as the goldenrod ball gallmaker, is a species of fly native to North America.  The species is best known for the characteristic galls it forms on several species in the "Solidago", or goldenrod, genus.  The fly’s eggs are inserted near the developing buds of the plant.  After hatching, the larvae migrate to an area below the plant’s developing buds, where they then induce the plant’s tissues to form into the hardened, bulbous chamber referred to as a gall.  "E. solidaginis"’s interactions with its host plant(s) and insect, as well as avian, predators have made it the centerpiece of much ecological and evolutionary biology research, and its tolerance of freezing temperatures has inspired studies into the anti-freeze properties of its biochemistry. Solidago simplex, the Mt. Albert goldenrod or sticky goldenrod, is a North American plant species in the genus "Solidago" of the sunflower family.  It is widespread across much of Canada, parts of the United States, and northeastern Mexico. Solidago, commonly called goldenrods, is a genus of about 100 to 120 species of flowering plants in the aster family, Asteraceae.  Most are herbaceous perennial species found in open areas such as meadows, prairies, and savannas.  They are mostly native to North America, including Mexico; a few species are native to South America and Eurasia.  Some American species have also been introduced into Europe and other parts of the world. Brintonia is a monotypic genus of flowering plants in the sunflower family, containing the single species Brintonia discoidea.  It is known commonly as the rayless mock goldenrod.  It is native to the southeastern United States, where it is distributed in Alabama, Florida, Georgia, Louisiana, and Mississippi. Solidago gigantea is a North American plant species in the sunflower family.  Its common names include tall goldenrod and giant goldenrod, in reference to its height of up to 2 m tall, rather large for the genus, smooth goldenrod and late goldenrod.  It is a widespread species known from most of non-arctic North America east of the Rocky Mountains.  It has been reported from every state and province from Alberta to Nova Scotia to Florida to Texas, and also from the state of Nuevo León in northeastern Mexico.
Answer: Solidago