25400
Contributions to botany In the late fifties , van Bruggen obtained from an aquarium-plant importer an Aponogeton species which he failed to be able to name using the existing literature .
 van Bruggen
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 van Bruggen