The scarlet leather flower potentially harmonizes with Southwest facing spaces. According to Feng Shui principles, Southwest is governed by the earth element. As the scarlet leather flower thrives in rough terrains that reflect the earth's resilience, this could suggest a mutual affinity. However, individual Feng Shui interpretations may vary.

The slash pine is considered agreeable in Feng Shui when placed towards the Northwest. The supporting reason could be its resilience and hardiness that matches the Northwest's defining element, metal, symbolising strength and endurance. Remember, perceptions of Feng Shui can vary greatly across different traditions and practitioners.

The alpine currant is generally compatible with an East-facing position. This direction correlates with the Wood element in Feng Shui, which promotes growth and renewal, much like alpine currant's natural tendencies. However, the plant's influence on Qi, or energy flow, could vary significantly according to individual perspectives.

The christmas-bells harmonizes well with East-facing environments. It brings a particular kind of energy which, informed by Feng Shui principles, may boost the Wood element usually thriving in such directions. However, be reminded that results could vary tremendously due to individual interpretations and applications of Feng Shui.

The sitka spruce is harmonious with Eastern facing placements, reflecting general Feng Shui principles. Known for its strong wood energy, it represents growth and vitality, syncing well with the East's embodiment of renewal and beginnings. Remember, Feng Shui is deeply personal; the sitka spruce's influence might differ based on individual interpretations.

The poorman's orchid personality is often considered vivacious, making it potentially harmonious or discordant depending on other energies present. Aligned with South-facing directions, this plant is seen to promote growth and transformation, harnessing the fire energy of the South. This is typically ideal for those seeking personal advancement or rejuvenation, but subjective outcomes may vary based on personal energies and the plant's overall placement.

The nutmeg and mace, with its unique properties, aligns harmoniously when situated in the Southwest quarter. This is attributed to the grounding energy it possesses, effectively complementing the Earth element associated with Southwest in Feng Shui. However, the complex nature of Feng Shui means the final assessment remains deeply personal.

Indian tobacco is said to bring an ambience of healthy liveliness when placed towards the South. This is due to its association with fire, aiding those who desire to welcome vibrant energy into their lives. However, it's essential to notice that the interpretation varies greatly among different schools of Feng Shui.