Han Sen walked to the banks of the river under the guise of fetching water, but he really wanted to perform a test.
He still had two waterdrops left to use, but the tree had spent its first waterdrop over the course of two days. Using the two waterdrops directly wouldn't be viable long term.
Han Sen wanted to look around for a few geno plants, to see if the black crystal would be willing to absorb their lifeforce.
The geno plants that could be found in the lands around the shelter were already owned, so he couldn't use those.
But Qu Lanxi said that the river was called Jade-Scale River, and its source resided someplace in Thorn Forest. Geno plants would most certainly live on the banks of such a river.
That being said, they'd only be normal geno seeds. And since they weren't cared for by others due to their lack of fruit, they wouldn't be missed.
Han Sen pretended to go get water so he could take a look at the wild geno plants.