The first one is similar to acanthocereus: shrubby plant with arching and angled stems, spines are short and stout. Flowers are very big and white, flower tubes have scales, but no spines. Mature fruits are red and globular with plenty of black small seeds in the white or no color pulp, texture of fruit is like watermelon, a little bit firmer, it tastes a little salty and a little sweet.
Adding some pictures that were taken two year ago when I grew it in a big pot for you to see to help me to identify it. Last year I put it down to the ground, it grows extremly fast, starts some blooms again last week.
![Image](http://www.cactiguide.com/forum/userpix/1703_1_3.jpg)
![Image](http://www.cactiguide.com/forum/userpix/1703_2_3.jpg)
![Image](http://www.cactiguide.com/forum/userpix/1703_3_2.jpg)
![Image](http://www.cactiguide.com/forum/userpix/1703_4_2.jpg)
![Image](http://www.cactiguide.com/forum/userpix/1703_5_2.jpg)
![Image](http://www.cactiguide.com/forum/userpix/1703_6_2.jpg)
![Image](http://www.cactiguide.com/forum/userpix/1703_7_2.jpg)
![Image](http://www.cactiguide.com/forum/userpix/1703_big_dragon_2.jpg)