Zanthoxylum hawaiiense is a small to medium-sized tree ranging from 1 to 8 meters in height, with trunks up to 25 cm in diameter. The bark varies from pale to dark gray, and the foliage is often lemon-scented. New growth on the plant can be glabrous, finely puberulent, or tomentose, with young branches featuring a pair of bud scales at their bases. The leaves are compound and alternate, with broadly deltate-ovate or lanceolate blades. When deltate-ovate, the lateral leaflets display asymmetry. Leaflets are thin to thick and coriaceous, measuring 3.4 to 12 cm in length and 1.5 to 7.5 cm in width. The lateral petiolules are articulated only at the base and are thickened near the leaflet, while the terminal petiolule is twice articulated. The flowers are unisexual and actinomorphic, usually 15 to 20 within the axillary, open, and cymose inflorescences 4 to 8 cm long. The calyx consists of 4 narrowly deltate sepals, and the corolla comprises four petals. Stamens are present in male flowers, with four glabrous stamens, and the ovary is superior and 1-carpellate in female flowers. The fruit is a falcate, obovoid follicle, 8 to 10 mm long, with a rugulose and pitted exocarp, containing a single, black, subglobose, compressed seed 7-8 mm in diameter. It inhabits dry forests on lava flows and is sometimes found in mesic forests between 550-1,740 meters.
Bean-shaped (Reniform): Resembling the shape of a kidney or bean.
Square or Oblong: Angular shape with all sides more or less equal or longer than wide.
Triangular: Three-sided shape, broadest below the middle.
Elliptic: Rounded at both ends. shaped like an ellipse or oval.
Ovate or Obovate: egg-shaped, broader at one end.
Linear: Extremely long and narrow, with sides usually parallel.
Round: Appears circular, with length and width roughly the same.
Cardioid (Heart-Shaped): One edge has a prominent double curve into two lobes.
Cylindrical: A cylinder with parallel sides and a circular cross-section.
Discoid: Resembling a disc or plate with two relatively flat surfaces.
Fusiform: Spindle-shaped, tapering at both ends.
Globose: Spherical.
Lenticular: Resembling a lens with two convex surfaces.
Ovoid: Egg-shaped.
Plano-convex: Having a flat ventral (planar) surface and a curved dorsal (convex) surface.
Polygonal: Having more than three flat faces meeting at angles.
Sectoroid: Resembling a segment of an orange with two relatively flat faces and one curved face.
Subglobose/ellipsoid: Inflated shape but less than spherical.
Trigonous: Having three faces that meet at a distinct angle; triangular in cross-section.
Endangered species (E) are species that are so rare they’re in danger of becoming extinct.
Threatened species (T) are species that are likely to become endangered within the foreseeable future throughout all or a significant portion of their range.
Species of Concern (SOC) are species about which there are some concerns regarding status and threats, but insufficient information is available to list the species under the Endangered Species Act (ESA).
Plant Extinction Prevention (PEP) is a state status for rare plants that focuses its efforts on species that have fewer than 50 remaining wild individuals.
Orthodox seeds (desiccation-tolerant): can be dried to an internal seed moisture of less than 12% water and stored at freezing temperatures.
Intermediate seeds (temperature-sensitive) tend to age faster than orthodox seeds and may have only a 5-year lifespan when stored at -20°C. They are recommended for storage at 5°C.
Recalcitrant seeds (desiccation-sensitive): cannot be stored in a conventional freezer as they cannot survive after drying and/or freezing at -20°C. They are recommended for cryopreservation storage.