Question

Is Pinus dioecious?

Answer 1

Pinus trees are evergreen coniferous resinous trees that are often known as pine. They are members of the Pinaceae family, which is classified as Coniferopsida in the Coniferales order. Pinus species are found across the Northern Hemisphere's temperate and sub-alpine areas, where they produce dense evergreen forests. They may reach a height of $80$ metres ($260$ feet).

Complete answer:
Before we answer this question, we must know the meaning of the term dioecious.
The term dioecious means that male and female gametes are produced on different plants. Many plant species which produce different plants for male and female flowers are called dioecious.
Pinus is a monoecious plant that reproduces by sporophytic generation. Although the microsporophyll (male) and megasporophyll (female) are produced on the same plant, they are generally found in distinct cones or strobilli.
Staminate strobilus and carpellate strobilus are the male and female cones, respectively.
Male cones are small, compact, oval structures that are around $2 - 3$ cm in length. They can be seen in bunches towards the tips of lengthy shoots. Each male cone has a central axis that is short and elongated, on which a great number of microsporophylls or stamens are spirally organized.
Female cones are bigger and more complex than male cones. They grow in clusters of $1 - 4$ in the axils of long shoots' scale leaves. They start off green, but eventually turn a brownish red hue. It begins to flower in the winter and is ready for pollination in the spring. It has a dry and stiff woody structure.

So, the answer is that Pinus is not dioecious.

Note:
Plants are classed as monoecious or dioecious depending on whether or not they have bisexual blooms. The flowers of monoecious plants are unisexual, although both pistillate and staminate blooms are present. Female flowers are pistillate, whilst male blooms are staminate. Pistillate flowers or staminate blooms can be seen in dioecious plants.