If you want flowers that last for months? Crown-of-Thorns is the best bet.
The Euphorbia milii, also know as Crown-of-Thorns, are very easy to grow, low maintenance plants with attractive blooms that can last long for months together.
Euphorbia hybrids are truly tough plants and can take just about anything including relatively dry or overly wet conditions, temperatures between 4 and 40+ deg C, part shade to full sun and a variety of growing media.
However, to give of their best they do require moderation in all the above
Euphorbia produce unisexual flowers. The inconspicuous male flowers occur in clusters and are reduced to a single red stamen, while the female flower consists of a single ovary (pistil) on a stalk (pedicel).
Euphorbia (Pink- White)
Euphorbia (Pink - Yellow)
Euphorbia (Red Mini)
Euphorbia Tirucalli (Pencil Tree)
Euphorbia tirucalli has unmistakable, brush-like branch masses that are a noticeable feature of the plant.
Euphorbia Leucodendron (Cat tails euphorbia)
Euphorbia leucodendron) is a succulent shrub or small tree made up of clusters of erect, joint spineless stems.