Melicope clusiifolia is a shrub or tree that reaches 2-10 m in height. New growth is glabrous to minutely scruffy and hirsute or densely yellowish brown or golden pilose to shaggy pilose. Leaves with a weak anise odor, in whorls of (2-)4(-8) per node, subcoriaceous to coriaceous, often brittle, variable in shape, obovate, oblong-spatulate, or elliptic-obovate, rarely oblong-elliptic, elliptic-ovate, or elliptic, (2.5-)5-30 cm long, (1.5-)2.5-6(-7.5) cm wide, primary lateral veins usually 14-20 pairs, connected by a weakly arched vein ca. 1-4 mm from the margin, primary lateral veins and submarginal vein only slightly more prominent than higher order venation, which forms an evident reticulate pattern, the upper surface usually glossy, glabrous or midrib sometimes short-hirtellous, lower surface generally paler, glabrate to puberulent or short-villous along midrib, sometimes more evenly over entire surface, margins sometimes recurved or revolute, apex rounded to subtruncate and usually emarginate, occasionally obtuse, base rounded, cuneate, or attenuate, petioles 0-40 mm long. Flowers perfect or functionally unisexual (and then plants dioecious), in glabrous, fasciculate cymes, initiated among leaves, usually maturing on naked stems below leaves, peduncles 0-4 mm long, pedicels 1-10 mm long, bracteoles minute, deltate; staminate flowers with calyx ovate, 3-4 mm long, glabrous or minutely ciliate, petals deltate-ovate, 4-8 mm long, glabrous, apex acute, ovary rudimentary, glabrous; pistillate flowers with sepals ovate, 2-3 mm long, glabrous or minutely ciliate, petals deltate, 3-6 mm long, glabrous, ovary glabrous, style ca. 2 mm long, stigma lobes thick, blunt. The fruits are capsules 8-18 mm wide, carpels connate 1/8-7/8 their length, 4-9 mm long, exocarp usually strongly wrinkled when dry, glabrous, endocarp glabrous. The seeds are 1–2 per carpel (cell); 4.2-6.5 mm long, glossy black when ripe; crustaceous; ovoid; sometimes angled from compression; embryo straight in fleshy endosperm; radicle short; cotyledons compressed; ovate; putamen brown; warty. It occurs in mesic to wet forests on all main islands except Ni‘ihau and Kaho‘olawe, between 300-1900 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.