from typing import List, Dict, Optional, Union, Any
import re

def validate_flower_name(name: str) -> bool:
    """
    Validate a flower name.

    Args:
        name: The flower name to validate.

    Returns:
        bool: True if the flower name is valid, False otherwise.
    """
    pattern = r'^[a-zA-Z\s]+$'
    return bool(re.match(pattern, name))

def get_flower_info(flower_name: str) -> Optional[Dict[str, Any]]:
    """
    Get information about a flower from an external API or database.

    Args:
        flower_name: The name of the flower.

    Returns:
        Optional[Dict[str, Any]]: A dictionary containing information about the flower, or None if not found.
    """
    # Implement logic to fetch flower information from an external source
    pass

def format_flower_list(flowers: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
    """
    Format a list of flower information dictionaries.

    Args:
        flowers: A list of dictionaries containing flower information.

    Returns:
        List[Dict[str, Any]]: A formatted list of dictionaries with flower information.
    """
    formatted_flowers = []
    for flower in flowers:
        formatted_flower = {
            'name': flower['name'],
            'description': flower.get('description', ''),
            'category': flower.get('category', ''),
            'image_url': flower.get('image_url', '')
        }
        formatted_flowers.append(formatted_flower)
    return formatted_flowers

def filter_flowers_by_category(flowers: List[Dict[str, Any]], category: str) -> List[Dict[str, Any]]:
    """
    Filter a list of flower information dictionaries by category.

    Args:
        flowers: A list of dictionaries containing flower information.
        category: The category to filter by.

    Returns:
        List[Dict[str, Any]]: A list of dictionaries containing flower information for the specified category.
    """
    filtered_flowers = [flower for flower in flowers if flower.get('category', '').lower() == category.lower()]
    return filtered_flowers

def search_flowers_by_name(flowers: List[Dict[str, Any]], search_term: str) -> List[Dict[str, Any]]:
    """
    Search for flowers by name in a list of flower information dictionaries.

    Args:
        flowers: A list of dictionaries containing flower information.
        search_term: The search term to use for filtering flower names.

    Returns:
        List[Dict[str, Any]]: A list of dictionaries containing flower information for matching flower names.
    """
    matching_flowers = [flower for flower in flowers if search_term.lower() in flower['name'].lower()]
    return matching_flowers