Brown dry tips of leaves only on main cola?

White hairs/pistils are the beginning of flowers. What you have circled, the lower one is known as a "pre-flower" and the top circle is an actual flower forming. Dead leaf tips are probably due to a combination of high temps, high humidity and low air flow. It won't really affect your plants too much, but open the doors/windows on hot days in the future.

Dead leaf tips, particularly around the top or main cola, can be due to several reasons in a greenhous: Nutrient Burn: Over-fertilizing can cause the tips of the leaves to turn brown and die. Check if you've been providing too many nutrients. Heat Stress: High temperatures, especially in a greenhouse, can cause this issue. Make sure there is adequate ventilation and that the temperature is not too high. pH Imbalance: Improper pH levels can affect nutrient uptake, leading to symptoms like dead leaf tips. Ensure your soil pH is within the optimal range (6.0-7.0 for soil). Happy growing

Estás fertilizando con algo?parece sobrefertilizacion, si si te recomiendo que tus próximos riegos los realices solo con agua con buen ph. Si, lo que marcas con rojo son los calices, felicidades 🙌 tu planta es hembra