The dendritic pattern develops where the river channel follows the slope of the terrain. The stream with its tributaries resembles the braches of a tree , thus the name dendritic. It also flows underneath a rock that is the same hardness.
ganga
Dendritic drainage patterns
Dendritic drainage patterns are tree like while trellis drainage patterns are formed when tributaries meet at right angles so they look like squares or rectangles.
Most Indo-Gangetic Rivers have dendritic (tree-like) drainage pattern.
It is Dendritic
The four major drainage patterns are dendritic, radial, rectangular and trellis. The factors that influence them are soil type, climate and the human interventions.
The st. Lawrence river is dendritic drainage.
dendritic drainage pattern
Dendritic
both
I would say Trellis because it doesn't look dendritic, but I can't be sure.
K