Hibiscadelphus hualalaiensis is a tree that reaches heights of 5 to 7 meters, with a trunk up to 30 cm in diameter characterized by smooth, grayish bark and prominent petiole scars on young branches, transitioning from glabrate to stellate puberulence. The leaves are simple and alternate, with ovate to orbicular blades 10–15 cm long, sometimes exhibiting 3–5 angles and a deeply cordate base with an open sinus. Margins range from entire to slightly undulate-dentate, supported by petioles 4–10 cm long and stipules that are subulate to triangular and caducous. The flowers are found near the ends of branches, usually 1-2 in the leaf axils, on pedicels ranging from 1.5 to 14 cm in length. The calyx is tubular to subsaccate, 1.5–3 cm long, and can be 2–3–cleft or 5-lobed. The corolla, typically zygomorphic (bilaterally symmetric), ranges from tubular to rotate or reflexed, with obovate petals, greenish-yellow on the outside, fading to purplish within, and measures 2–5.5 cm in length. The stamens are numerous and monadelphous, forming a staminal column that is exserted or exposed by the spreading lower petals. The ovary is superior with axile placentation, leading to woody, oblong-ovoid to ellipsoid-ovoid capsules that are grooved and apiculate, measuring 2.2–3 cm in length, and dehiscent loculicidally with a strongly developed mesocarp. The seeds are reniform, up to 9 mm long, densely grayish white lanate, with or without endosperm. It was found in dry to mesic forests and on lava flows between 600 – 1525 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.