Draft:Santanum Involutum

Santalum involutum is an endangered small tree belonging to the Santalaceae family, commonly known as sandalwood.

Characteristics

It typically reaches a height of 4 to 8.3 m (13 to 27 ft) and has smooth, charcoal-colored bark. The leaves are coriaceous (papery) and arranged opposite each other, often drooping. They are linear-elliptic in shape, measuring 5.7 to 8 cm (2.2 to 3 in) in length and 1.4 to 1.8 cm (0.6 to 0.7 in) in width. The leaves have rolled-in sides that give them a tubular appearance. The inflorescences, called cymes, are 3 to 5 cm (1.2 to 2 in) long and bear 5 to 15 flowers, with the terminal flower blooming first.

Flowers and Fruits

The flower stalk, known as the peduncle, is 9 to 16 mm (0.4 to 0.6 in) long. The flowers themselves are campanulate (flaring) to cylindrical in shape, with four lobes. They are initially greenish-white, but may turn red as they age. The fruits, known as drupes, are fleshy and contain a single seed. They measure 15 to 20 mm (0.6 to 0.8 in) in length and have an apical ring and a slender tip of 3 to 5 mm (0.1 to 0.2 in).

Origins

Santalum involutum and S. pyrularium are two species that are found exclusively on Kauai. While they may share similarities in their physical characteristics, they are genetically distinct from each other. The evidence from phylogenetic studies, which include the analysis of both nrDNA and cpDNA data, suggests that S. pyrularium originated from a separate colonization event within the red-flowered clade. On the other hand, S. involutum is more closely related to the white-flowered S. ellipticum clade. DNA analysis also indicates that S. involutum may have ancient hybrid origins, representing a combination of genetic material from both the white- and red-flowered Hawaiian Santalum clades (Harbaugh et al. 2010, entire).

References