This plant is sourced from Tropica Aquarium Plants.  This is what Tropica describes this plant:

Rotala 'Bonsai' is best described as a compact, moderate-growing version of Bacopa Caroliniana. Plant in small groups and trim often. Cuttings may be re-planted in the group to achieve a more dense group or carpet. 
At high light may the tip of the stems become reddish, at lower light will the leaves become larger and the plant less compact. 
Rotala  ‘Bonsai’ is particularly suitable for nano-aquariums. 

INSTRUCTION:

• Type: Stem
• Origin: Cultivar
• Growth Rate: Slow
• Height: 5-20+cm
• Light Demand: Medium
• CO2: Medium

Attention! Please read the following important notes before ordering any live plants:

For all customers outside of California, please do not order plants via UPS Ground shipping or USPS first class mail, there is a very high chance they will not make it alive.  No live arrival guarantee for USPS first class, UPS ground, and FedEx ground.  USPS priority mail is guaranteed with a 50% refund/credit.  Although USPS priority mail is the most popular and ships fine in most cases, occasionally it could get mishandled or delayed, so please order at your own risk.

*Please refer to the link here for more details of our Live plants guarantee policy before you make the purchase.

Due to the fact that live plants are highly perishable, we strongly recommend the purchase of a thermal bag and cold pack set ($5 each) with each plant order value under $50 (not including shipping).

We will include the thermal bag and cold pack set for FREE if each plant order exceeds $50 (Free shipping over $50).