“Arethusa” by Percy Bysshe Shelley
Arethusa arose
From her couch of snows
In the Acroceraunian mountains,
From cloud and from crag,
With many a jag,
Shepherding her bright fountains.
She leapt down the rocks,
With her rainbow locks
Streaming among the streams;
Her steps paved with green
The downward ravine
Which slopes to the western gleams;
And gliding and springing
She went, ever singing,
In murmurs as soft as sleep;
The Earth seemed to love her,
And Heaven smiled above her,
As she lingered towards the deep.
Then Alpheus bold,
On his glacier cold,
With his trident the mountains strook;
And opened a chasm
In the rocks – with the spasm
All Erymanthus shook.
And the black south wind
It unsealed behind
The urns of the silent snow,
And earthquake and thunder
Did rend in sunder
The bars of the springs below.
And the beard and the hair
Of the River-god were
Seen through the torrent’s sweep,
As he followed the light
Of the fleet nymph’s flight
To the brink of the Dorian deep.
‘Oh, save me! Oh, guide me!
And bid the deep hide me,
For he grasps me now by the hair!’
The loud Ocean heard,
To its blue depth stirred,
And divided at her prayer;
And under the water
The Earth’s white daughter
Fled like a sunny beam;
Behind her descended
Her billows, unblended
With the brackish Dorian stream:
Like a gloomy stain
On the emerald main
Alpheus rushed behind,
As an eagle pursuing
A dove to its ruin
Down the streams of the cloudy wind.
Under the bowers
Where the Ocean Powers
Sit on their pearled thrones;
Through the coral woods
Of the weltering floods,
Over heaps of unvalued stones;
Through the dim beams
Which amid the streams
Weave a network of coloured light;
And under the caves,
Where the shadowy waves
Are as green as the forest’s night:
Outspeeding the shark,
And the sword-fish dark,
Under the Ocean’s foam,
And up through the rifts
Of the mountain clifts
They passed to their Dorian home.
And now from their fountains
In Enna’s mountains,
Down one vale where the morning basks,
Like friends once parted
Grown single-hearted,
They ply their watery tasks.
At sunrise they leap
From their cradles steep
In the cave of the shelving hill;
At noontide they flow
Through the woods below
And the meadows of asphodel;
And at night they sleep
In the rocking deep
Beneath the Ortygian shore;
Like spirits that lie
In the azure sky
When they love but live no more.

I could spend a lot of time commenting on the Greek myth used in this poem – perhaps people have even written books about it.
And the meadows of asphodel
Just about the most evocative line ever. The asphodel is in fact an extremely unspectacular plant, but appropriate for scenes outside the real world, where everything is ghostly. It is far less attractive than the daffodil (which used to be affodil) but for me conjures up much far stronger images.
Especially for you Jeremy, I have found a picture of an asphodel and added it below the poem. Is this the variety you had in mind? If you would like to contribute a piece on the Arethusa myth, I think it would go very nicely here in my “Borrowed Words” section
Not a specific contribution at present, but just to mention that any lover of Homer would appreciate the classical references, which are plentiful. In the Odyssey, Homer makes three references to ασφοδελόν λειμώνα, the asphodel meadow, with dead heroes in the underworld striding through them. (See the Wiki reference to Asphodel Meadows. [The entry is incorrect, it should be singular]). The plants were associated with death. It is only a guess that the genus asphodelus corresponds to the Homeric asphodel.
The Arethusa myth is a very minor one – I’ll do some homework and see where it comes from.
I can’t find anything else worth mentioning about the Arethusa myth, other than her name is a feminine participle, like Hypotenuse. But that is probably not worth mentioning anyway, so I won’t. On my musings about Arethusa I was sidetracked by Greek tragedy and decided to read Sophokles ‘Oedipus Rex’ yet again, in small doses. The play is steeped in layers of meaning and ambiguities, and I was pondering the text and feeling quite clever, when an ant proceeded to take a walk over the book, walking as ants do in a semi-random fashion, stopping here and there on the page, and finally walking off. I wondered whether the ant was blissfully unaware of the literary treasure he was wandering over. Then, I suddenly realized with horror that I was feeling superior to the ant, in the act of hubris – the very same error as the one at the heart of the Oedipus plot. I then wondered whether I was in fact appreciating the text on a level significantly higher than the ant was. Food for thought.