Beach cabbage or half flower is a common shrub of the beaches and shores of the Arabian Sea, the tropical Indian Ocean, and tropical Pacific islands.
I had already prepared these images before noticing that a former UBC Botanical Garden colleague of mine, Jackie Chambers, had already written a comprehensive entry for Scaevola taccada. I decided to share the photos anyway, since they cover flower and fruit to habit and habitat, but I suggest (re)reading Jackie’s excellent write-up for more about the species.
These particular plants in today’s photographs are from genetic material native to the site, though perhaps planted. The technical report, Rare plant stabilization projects at Hawai’i Volcanoes National Park, 1998-2008 (PDF), notes that Scaevola taccada was one of four species used as matrix plantings along the coastal strand ecosystem within the park:
The coastal strand environment of Hawai’i Volcanoes National Park lies in a narrow band under the influence of salt spray, 15-100 m or more from the shoreline. In shoreline areas with high sea cliffs, the strand is typically narrow; in low bluff or beach areas, the strand may extend further inland.
Today’s photos are from one of the high sea cliffs areas, near the famous Hōlei Sea Arch.
As one of the matrix plantings, Scaevola taccada was planted in significant numbers to augment the naturally-occurring population. The intent was to provide additional habitat for its associated rare and uncommon species such as Ischaemum byrone and Portulaca villosa. The results were not too heartening for most species in the study, though the Scaevola taccada did well.
Of these three species as examples, fewer than 1% of the original plantings of Ischaemum byrone remained after nearly 10 years. None of the Portulaca villosa survived over that length of time. For Scaevola taccada, the number was 143% over the monitored time (explained by establishment of seedlings or small plants directly from the plantings). At the least, the researchers were able to generate suggestions for future restoration efforts with some of the rare species within the report.