Question: Which genus of plant-life as a larger area of habitation, Centaurea or Commidendrum?
Context: Centaurea uniflora, common names: Singleflower Knapweed, is a perennial herbaceous plant belonging to the genus "Centaurea" of the Asteraceae family. Centaurea scabiosa or greater knapweed is a perennial plant of the genus "Centaurea".  It is native to Europe and bears purple flower heads. The index of dissimilarity is a demographic measure of the evenness with which two groups are distributed across component geographic areas that make up a larger area.  The index score can also be interpreted as the percentage of one of the two groups included in the calculation that would have to move to different geographic areas in order to produce a distribution that matches that of the larger area.  The index of dissimilarity can be used as a measure of segregation. Centaurea triumfettii, common names: Squarrose Knapweed, is a plant belonging to the genus "Centaurea" of the "Asteraceae" family. Commidendrum is a genus of trees and shrubs in the sunflower family endemic to the island of Saint Helena in the South Atlantic Ocean.  The vernacular name is "gumwood" or "scrubwood". Centaurea ( ) is a genus of between 350 and 600 species of herbaceous thistle-like flowering plants in the family Asteraceae.  Members of the genus are found only north of the equator, mostly in the Eastern Hemisphere; the Middle East and surrounding regions are particularly species-rich.  Common names for this genus are centaury, centory, starthistles, knapweeds, centaureas and the more ambiguous "bluets"; a vernacular name used for these plants in parts of England is "loggerheads" (common knapweed).  The "Plectocephalus" group – possibly a distinct genus – is known as basketflowers.  "Cornflowers" is used for a few species, but that term more often specifically means "C. cyanus" (sometimes also called "basket flower").  The common name "centaury" is sometimes used, although this also refers to the unrelated plant genus "Centaurium". Centaurea hermannii, is a perennial herbaceous plant belonging to the genus "Centaurea" of the Asteraceae family.  It is an endemic plant of Turkey and found only in Çatalca Peninsula, and threatened by habitat loss. The Saint Helena gumwood (Commidendrum robustum) is a species of tree endemic to Saint Helena, Ascension and Tristan da Cunha.  Though it is now comparatively rare, it was once one of the most abundant trees of mid-elevations of the island of Saint Helena in the South Atlantic Ocean.  A small tree to 7–8 m, it was cut extensively for fuel in the early years of settlement of the island by the English East India Company.  It has given its name to certain placenames on the island such as "Gumwoods".  It is one of several species in the endemic genus "Commidendrum". Urophora quadrifasciata is a species of tephritid or fruit flies in the genus "Urophora" of the family Tephritidae.  The host plant for the larvae is usually a knapweed ("Centaurea" sp), and because of this, it is used to control "Centaurea maculosa". Urophora jaceana is a species of tephritid or fruit flies in the genus "Urophora" of the family Tephritidae.  The host plant for the larvae is usually "Centaurea nigra" or "Centaurea debeauxii".
Answer: Centaurea