import re


def herbarium(image_file):
    """Map the image file name to a herbarium."""
    image_file = str(image_file)
    if image_file == 'nan':
        return ''
    image_file = image_file.upper()
    parts = re.split(r'[_-]', image_file)
    return parts[1] if parts[0] == 'TINGSHUANG' else parts[0]