Isabella was born in Scotland and migrated around the globe with her family to New Zealand in 1861. There she began her studies in botany. In 1863, she moved to Niihau, the northernmost island of the Hawaiian Archipelago and began to explore the vegetation of both Niihau and neighboring Kauai.
Thanks to her families' relationship with the native population on both islands, Isabella was able to collect extensive information about her botanical discoveries. She recorded their vernacular names, medicinal properties, habitats, and flowering seasons.
The following collection was made upon those two northern islands and introduced the world to an exotic, endemic, vanishing flora. Indigenous Flowers of the Hawaiian Islands provides a measure for the impact of human activity on the fragile ecosystems of those two Hawaiian islands. Isabella Sinclair's work stands as a strong proponent for plant conservation, and her breadth of botanical experiences in the Pacific gave her unique insight into the effects of humanity on the delicate local flora and fauna. Considering that the flowering plants of the islands in this collection come in more than four hundred varieties, it is far from exhaustive. But her studies still stand on their own as a celebration of the beauty of the flora of Hawaii.