Phyllostegia pilosa is a suberect perennial herb with moderately short-hirtellous stems featuring spreading trichomes that are usually somewhat antrorsely oriented. The leaves are simple and opposite, with ovate to occasionally elliptic-ovate blades measuring 8–14 cm long and 3–4.5(–7.5) cm in width. The leaf apex ranges from acute to short-acuminate, while the base is subcordate or occasionally truncate. The lower surfaces of the leaves are glandular-dotted and short-hirtellous, becoming densely so along the veins. The trichomes on these surfaces are erect to somewhat crinkly, measuring 0.2–0.3 mm in length. Leaf margins are evenly crenate, and the petioles are 2.5–3.2(–4.5) cm long. The flowers are 6–12 per verticillaster (inflorescence that resembles a whorl but consists of two crowded cymes on either side of the stem) in relatively narrow, usually simple, terminal, bracteate inflorescences measuring 7–12 cm long. These are pubescent, with spreading to erect trichomes, usually 0.1–0.2 mm long, and pedicels are 0.6–1.8 mm long. The calyx, measuring 3.2–3.6 mm in length, enlarges in fruit, is short-hispidulous, denser towards the apex, and inconspicuously glandular-dotted. It is typically 5-toothed, with linear-delicate teeth measuring 0.7–1.6 mm long. The corolla is bilabiate and white, with a slender, slightly curved tube 7.3–10 mm long that is short-villous with somewhat appressed trichomes and inconspicuously glandular-dotted. The lower lip of the corolla measures 3.5–5.5 mm in length. The stamens are 4 in number, with both pairs of similar size or the upper pair slightly longer, ascending the upper corolla lip. The ovary is superior and 2-carpellate. The fruits are nutlets approximately 2–3 mm long, 1-seeded, dark green to black, drupaceous, with a fleshy exocarp, obovoid shape, and slightly winged margins. These nutlets are obliquely attached at the connate base and spread and are exserted from the calyx at maturity. The seeds within these nutlets lack or have scanty endosperm and are oily. It was found in wet montane forest habitats.
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.