Bidens hillebrandiana subsp. hillebrandiana is an erect or usually decumbent, slightly suffrutescent perennial herb, reaching 0.2–0.3 meters in height. The leaves are rarely simple, usually pinnately or bipinnately compound, measuring 3.5–8 cm long, including the petiole. Leaflets number 3–9 are fleshy, ovate, and typically 5–25 mm long and 2–15 mm wide. Surfaces are glabrous or sparsely pubescent, and margins are crenately toothed or lobed. The flower heads are solitary or 1–3 (sometimes 4) per inflorescence, borne on peduncles 2–8.5 cm long, in simple or compound cymes terminating the main stem and lateral branches. Heads are 1.4–2.4 cm in diameter, including ray florets. Peduncles measure 0.2–8.5 cm long and are glabrous or sparsely pubescent. Outer involucral bracts are 2–3 mm long, with distinct, short inner bracts that often do not cover the flower buds. Each head contains 5–6 sterile ray florets with yellow rays, 9–12 mm long and 3–4 mm wide, and 11–21 perfect disk florets with yellow corollas. The pappus consists of 2 awns, 1–2 mm long. The fruit is a simple, dry achene (cypsela). These achenes are gray to grayish black, straight, wingless, and measure 6–8 mm long and 0.8–1.2 mm wide. It is found on coastal bluffs and sea cliffs.
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.