What your describing is called Guttation, and what your seeing is a sap exudate.... At night, transpiration usually does not occur because most plants have their stomata closed. When there is a high soil moisture level, water will enter plant roots, because the water potential of the roots is lower than in the soil solution. The water will accumulate in the plant, creating a slight root pressure. The root pressure forces some water to exude (most oftenly) through special leaf tips or edge structures, hydathodes, forming drops. Root pressure provides the impetus for this flow, rather than transpirational ascent. This sap exudate can be clear, tan, brown or even blood red(The red colour is due to haematin compounds and anthocyanin pigments that naturally build up in some varieties; The red colour may also indicate a nutrient deficiency, notably of nitrogen, phosphorus, potassium, or magnesium) This sap usually contains a variety of organic and inorganic compounds, mainly sugars, and mineral nutrients, and potassium. Upon drying, a white crust remains on the tissue surface. Guttated sap exudates most commonly exude from cannabis, along both sides of the leaf axil, where the petioles attach to the stem. Though Guttations typically exude(in most plants) through modified leaf stomata known as hydathodes, in cannabis guttations most commonly exude at the leaf axil, or another part of the stem via a stoma .
