Uyupampensis x Val VRG (Yearlings)

cv. Uyapampensis" on Trichocereus forums indicates that this is a specific cultivar of the Trichocereus uyupampensis (or Echinopsis uyupampensis) species, according to Reddit posts. The use of "cv." denotes a cultivated variety, suggesting it's a specific form selected and propagated by humans. 

Here's a summary of the information gathered from Trichocereus forums about Trichocereus uyupampensis, which may relate to the "cv. uyapampensis":

Description: Trichocereus uyupampensis is a shrubby cactus species that typically grows to 1-2 meters in height with a diameter of 4-8 cm. It has 7-9 ribs that are narrow and flat, and the stems turn gray-green with age. The areoles are small and light brown, and they have 8-10 irregularly arranged spines that are black and brown.

Origin: The species is native to parts of Bolivia and Peru, specifically around Uyupampa in Peru. It was first described by Curt Backeberg in 1936.

Flowers: The flowers are funnel-shaped and pale yellow to white, with reddish exteriors, and they can be quite large, measuring 13-19 cm long. They open at night, and the flower buds are covered with hairs.

Cultivar Discussion: One Reddit user mentions a "cv. uyapampensis" they own which has a typical Trichocereus pachanoi growth structure but is extremely blue. They note that the part they received was shorter-spined and more notched, resembling Trichocereus ichoca. This suggests that "cv. uyapampensis" may be a selected form with unique traits like intense blueness or specific spine characteristics.

Related Species: The discussions also mention that Trichocereus uyupampensis can be easily mistaken for Trichocereus bridgesii or Trichocereus cuzcoensis. There is also discussion about the reclassification of Trichocereus validus as a synonym of Echinopsis uyupampensis. 

Based on the information, "cv. uyapampensis" likely refers to a specific cultivated variety of Echinopsis uyupampensis selected for traits like its distinctive blue color. Further research into online forums or dedicated cactus communities may reveal more details about this specific cultivar, including its origin, characteristics, and cultivation practices

"VRG" (Vari Red Grandi):

This likely refers to a Trichocereus variety known for its "Vari Red" characteristics, possibly hinting at reddish spines or a reddish tint to the epidermis, and perhaps a "Grandi" (grandiflorus) influence which can contribute to large, showy flowers. VAL VRG is a seed grown Misplant hybrid, a unique cross of Validus and Variegated Red Grandiflorus. This heavily variegated plant produced several flowers in 2023. Often used for creating wonderful variagated hybrids.