The wax plant embodies a unique balance of Yin and Yang, due to its thick leaves and heart shape. It's considered harmonious when placed in an East-facing area. This direction is traditionally associated with health and family, which aligns well with the plant's heart-shaped leaves symbolizing love and unity. This placement should harmonize the energy flow but remember, Feng Shui is highly personal and dependant on individual perception.

The bluebead Lily exhibits a subtle yet profound blend of energy, likely to synergize well when placed in northern-facing settings. In Feng Shui, north is linked with water element—often symbolizing wisdom and reflection. The bluebead Lily's deep green leaves and blue berries can enhance these energies, creating a restful and introspective atmosphere. Please note that these observations are suggestive rather than absolute, as Feng Shui is a complex, personalized art.

The musk strawberry aligns well with West-facing elements, subtly enhancing the energies of the space. This direction mingles with the plant's inherent resilience, nourishing positive relationships and inviting creativity. Its compatibility is a matter of vibrant visual representation, setting a harmonious balance with the surrounding environment. However, individual experience and resonance with the plant remains paramount in Feng Shui application.

Japanese sweet flag's compatibility with North-facing direction in Feng Shui is seen as auspicious due to its noted resilience and year-round greenery, representing steady growth and prosperity. However, its appropriateness may vary based on individual circumstances and orientations, underscoring the context-specific and interpretive variedness of Feng Shui wisdom.

Baby lime is often regarded in Feng Shui as a beacon of positivity and renewal. It's mildly compatible with East-facing spaces, attributed largely to the belief that this direction harnesses the plant's vibrant, energy-invigorating attributes. Indisputably, the interplay between Feng Shui, baby lime, and personal perception is almost mystical, reminding us of the subjective nature of this ancient art form.

Common Speedwell holds a special place in Feng Shui as it's believed to balance Yin and Yang energies. Facing Northeast signifies growth and knowledge, and common Speedwell, with its gentle, calming influences, is considered enhancing for this direction. It is however critical to remember that placement should depend upon individual spatial layouts and energy flows. The true harmony lies in interpreting and adapting Feng Shui to personal needs.

The large-lipped encyclia is fairly compatible with Feng Shui principles. Particularly when placed in a North-facing direction, this plant can potentially induce a sense of calm and serenity, beneficial in nurturing introspection, due to its robust green foliage symbolizing growth and renewal. However, like with all Feng Shui practices, the effect is highly subjective and varies greatly among individuals.

The saguaro, in the realm of Feng Shui, is considered a commanding embodiment of steadfastness and longevity, mirroring the principles of Earth and Metal. This makes its compatibility with the Northeast, an Earth element direction, reasonably harmonious. However, due to the unique nature of Feng Shui, individual experiences could differ, thus making its efficacy subjective.