Up to four species of this group may occur in the same place.

They are found throughout the world, with most species occurring in hot countries.

There are also reports that this species occurs in Iraq.

The species may occasionally occur there in very high numbers.

Around 5000 to 6000 species of plant occur naturally in Japan.

An indigenous species may occur in areas other than the one under consideration.

Up to four species of the group may occur in a single locality.

The area in which the species occur is going through urban expansion at a rapid rate.

A few species occur in summer rainfall parts of southern Africa.

Similar species frequently occur in the same habitat and are often difficult to tell apart.