This is close and clear: Morn must be near.
FESTUS.

Best ope the casement: see, The night, late strewn with clouds and flying stars, Is blank and motionless: how peaceful sleep The tree-tops all together! Like an asp[6] The wind slips whispering from bough to bough.
* * * PARACELSUS.

See, morn at length.

The heavy darkness seems Diluted, grey and clear without the stars; The shrubs bestir and rouse themselves as if Some snake, that weighed them down all night, let go His hold; and from the East, fuller and fuller, Day, like a mighty river, flowing in; But clouded, wintry, desolate and cold.
That is good, clear, and sufficient; and there the description should end.

But Browning, driven by some small demon, adds to it three lines of mere observant fancy.
Yet see how that broad prickly star-shaped plant, Half-down in the crevice, spreads its woolly leaves, All thick and glistening with diamond dew.
What is that for?
To give local colour or reality?
It does neither.