If I remember correctly, Walmart does not have silt plants, just plastic. :/ Most Walmarts do have a glow-in-the-dark version of this plant
. They also have a glow-in-the-dark type of small cave that I would have purchased if it had been a natural color. I'm not sure how your fish will react to a glow-in-the-dark ornament, but my betta does love that type of plastic plant (mine does not glow). I was a wee bit worried it'd be too pokey, etc., but he's thus far been fine. In my opinion, the rest of Walmarts' caves or ornaments seemed to have too many sharp edges, and I'm too lazy to file them down. (I'm a long-time employee of Walmart... which is why I feel like an encyclopedia when it comes to what we carry LOL).
Some Walmarts have random live plants in their aquariums, but you would totally have to quarantine/sanitize the snot out of them. o.O
And yeah, their live plant bulbs can be hit-and-miss. I've had packages where all the bulbs sprouted, and ones where only one of the four bulbs sprouted. :/
Petsmart and Petco would probably carry java ferns in those plastic tubes usually on display near the end of an aisle (called an end-cap), if you can get to one of those stores. I believe it depends on the store what exactly they have in stock.
Aaaaand you can buy plants online from eBay or Aquabid, but, again in my opinion, paying for shipping is a pain.