Question: Which genus is in the verbena family, Citharexylum or Laelia?
Context: Citharexylum spinosum is a species of flowering plant in the verbena family, Verbenaceae, that is native to southern Florida in the United States, the Caribbean, Guyana, Suriname, and Venezuela.  Common names include Florida fiddlewood and Spiny fiddlewood. Aloysia citrodora is a species of flowering plant in the verbena family Verbenaceae, native to western South America.  Common names include lemon verbena and lemon beebrush.  It was brought to Europe by the Spanish and the Portuguese in the 17th century and cultivated for its oil. Verbena simplex, commonly known as narrowleaf vervain, is an herbaceous perennial plant in the verbena family.  It is native to eastern North America where it is found in open, dry, habitats on calcareous soil.  It is tolerant of disturbance, and is often seen in pastures and roadsides with sparse vegetation. Citharexylum berlandieri is a species of flowering plant in the verbena family, Verbenaceae, that is native to the Lower Rio Grande Valley of Texas in the United States and Mexico as far south as Oaxaca.  Common names include Tamaulipan fiddlewood, Berlandier fiddlewood, negrito fiddlewood, negrito, and orcajuela.  It is a shrub or small tree, reaching a height of 6 m .  The type specimen of this species was collected from the hills near Las Canoas, San Luis Potosí by Cyrus Pringle in 1890.  It was described as a new species the following year by Benjamin Lincoln Robinson, who chose the specific epithet to honour French naturalist Jean-Louis Berlandier. Verbena bonariensis (purpletop vervain, clustertop vervain, Argentinian vervain, tall verbena, or pretty verbena) is a member of the verbena family cultivated as a flowering annual or herbaceous perennial plant.  In USA horticulture, it is also known by the ambiguous names "purpletop" (also used for the grass "Tridens flavus") and "South American vervain" (which can mean any of the numerous species in the genus "Verbena" occurring in that continent).  For the misapplication "Brazilian verbena" see below. Stachytarpheta is a plant genus in the verbena family (Verbenaceae).  The flowers are rich in nectar and popular with many butterflies, such as the South Asian crimson rose ("Atrophaneura hector"), Malabar banded swallowtail ("Papilio liomedon"), and grass yellow ("Eurema hecabe") and hummingbirds.  Several species in this genus are known as porterweeds. Laelia is a small genus of 25 species in the orchid family (Orchidaceae).  "Laelia" species are found in areas of subtropical or temperate climate in Central and South America, but mostly in Mexico.  "Laelia" is abbreviated L. in the horticultural trade. Citharexylum is a genus of flowering plants in the verbena family, Verbenaceae.  It contains shrub and tree species commonly known as fiddlewoods or zitherwoods.  They are native to the Americas, ranging from southern Florida and Texas in the United States to Argentina.  The highest diversity occurs in Mexico and the Andes.  The generic name is derived from the Greek words κιθάρα ("kithara"), meaning "lyre", and ξύλον ("xylon"), meaning "wood," referring to the use of the wood in the sounding boards of string instruments. Several species, especially "C. caudatum" and "C. spinosum", are cultivated as ornamentals. Phyla is a genus of eustarid plants in the verbena family, Verbenaceae.  The name is derived from the Greek word φυλή ("phyle"), meaning "tribe", and most likely refers to the tightly clustered flowers or the spreading, mat-like growth.  Members of the genus are known generally as fogfruit or frogfruit.  Species once classified in the genus "Lippia" may be known by the common name lippia.  Some species, e.g. Aztec Sweet Herb ("P. dulcis"), are used in cooking. Stachytarpheta cayennensis is a species of flowering plant in the verbena family known by many English language common names, including blue snakeweed, Cayenne snakeweed, dark-blue snakeweed, bluetop, nettle-leaf porterweed, rattail, rough-leaf false vervain, blue rat's tail, Brazilian tea, Cayenne vervain, false verbena, joee, nettleleaf velvetberry, and Cayenne porterweed.  Names in other languages include honagasō (Japanese), gervão-urticante (Brazilian Portuguese), piche de gato, rabo de zorro (Spanish), herbe á chenille, herbe bleue, queue de rat (French), ōi, ōwī (Hawaiian), and tiāki (Māori).  It is native to the Americas, from Mexico south through Central and South America to Argentina, as well as many islands of the Caribbean.  It is known in many other parts of the world as an introduced species, including regions in Africa, India, Indonesia, Australia, Florida in the United States, and many Pacific Islands.  Its distribution is now considered pantropical.  In many places it has become an invasive species.
Answer: Citharexylum