Complex sentence: Original "Tulipa" species can be obtained for ornamental purposes, such as "Tulipa tarda" and "Tulipa turkestanica" these are referred to as species or botanical tulips, and tend to be smaller plants but better at naturalising than the cultivated forms.
Split into simpler sentences: Original "Tulipa" species can be obtained for ornamental purposes, such as "Tulipa tarda" and "Tulipa turkestanica". These are referred to as species, or botanical, tulips, and tend to be smaller plants but better at naturalising than the cultivated forms.