The malabar gourd aligns well with Southwest facing directions. The plant's vigorous growth symbolizes prosperity, which is resonant with the element of Earth prevailing in the Southwest, promoting stability and nourishment. As Feng Shui is largely subjective, the actual impact might differ based on individual environments and contexts.

The european bur-reed harmonizes well with North-facing spaces, perhaps due to its affinity for cooler, damp environments. This adaptation reflects in its spiritual energy, exhibiting a soothing and harmonious vibe. However, always remember that Feng Shui interpretations can vary greatly based on individual perceptions and circumstances.

The alkali sacaton plant, by Feng Shui principles, exhibits a harmonious interplay that nurtures growth and prosperity. Its robust nature – often synonymized with resilience and perseverance – bodes well with the East direction, traditionally associated with family, health, and sunrise, signifying a fresh start or new beginning. However, it's prudent to observe its influence within your personal space, as Feng Shui interpretations can vary.

The bear's paw plant carries a subtle air of resilience and perseverance, echoing with the stable energy of the Earth element in Feng Shui. It is especially harmonious when placed in the Northeast, as this direction is associated with the Earth element, thus complementing bear's paw's inherent qualities. However, one should always feel the space and arrange plants with personal comfort in mind, to fully embrace the diverse possibilities of Feng Shui.

The cow lily is known to adequately harmonize with North-facing directions in Feng Shui. This stems from its perceived water-element properties which traditionally mingle well with the Water element symbolic to the North. The interpretation of its compatibility however, remains largely subjective and is open to personal interpretation.

The wax plant is generally adaptable in Feng Shui contexts due to its resilient nature. It's ideal for an Eastern-facing environment, as east symbolizes rebirth and new beginnings, mirroring the plant's tenacity. Nevertheless, its compatibility could vary with personal energy influences, so observing its behavior in your specific setting is crucial.

The greater pond-sedge brings a balanced synergy when it faces North, often associated with water in Feng Shui, reflecting the plant's natural aquatic habitat. However, like much of Feng Shui, compatibility varies based on individual circumstances and personal energy. Thus, it may not be universally applicable.

In Feng Shui, whitebark pine harmonizes well with the Northwest, imbuing an essence of stability and tranquility. As Northwest is connected with 'metal' element in Feng Shui, and whitebark pine is a representative of 'wood', this could maintain a balance, as wood feeds metal in the productive cycle. However, personalized analysis is encouraged to ascertain the exact influence on your environment.