Flora of North America species comparison

prostrate to erect, often zigzagged, reddish brown, simple or branched from base, wiry, 2–30 cm, papillose-scabrid-ulous.

erect or ascending, rarely prostrate, straight or zigzagged, 4-gonous, ribs obscure or absent, smooth or papillose-scabridulous.

evenly distributed or crowded at branch tips, articulated to ocreae, basal leaves persistent, hardly reduced distally;

ocrea 1–4 mm, papillose-scabridulous, proximal part cylindric, distal part entire or dentate-lacerate;

petiole 0.1–3 mm;

blade 1-veined, not pleated, narrowly elliptic, elliptic, ovate, obovate, or subround, 6–27 × 3–8 mm, margins flat, smooth, irregularly thickened or papillose-denticulate, apex apiculate, green adaxially.

ocrea 4–8-veined, proximal part not pruinose;

petiole (or blade when petiole absent) articulated or not to ocrea;

blade narrowly linear to subround, rarely coriaceous (P. paronychia, P. shastense, and P. utahense), margins smooth or papillose-denticulate, not rugulose, rarely glaucous adaxially (P. nuttallii); 1-veined or venation parallel (3-veined), secondary veins not conspicuous.

axillary;

cymes from near stem and branch bases, sometimes also crowded at branch apices, 1–3-flowered.

usually axillary and terminal, sometimes entirely axillary;

cymes 1–6-flowered.

enclosed in ocreae, erect to spreading, 2–3 mm.

erect to spreading or reflexed, 0.1–6 mm, sometimes absent.

semi-open or closed;

perianth 1.8–2.5 mm;

tube 22–29% of perianth length;

tepals overlapping, greenish with narrow white or pink margins, almost sepaloid, oblong, cucullate, ± navicular, apex rounded;

midveins thickened, unbranched;

stamens 8.

open, semi-open, or closed;

tepals ± monomorphic, outer tepals equaling or somewhat larger than inner, (dimorphic, with outer tepals shorter than inner in P. heterosepalum), apices of outer tepals rounded or acute to acuminate;

anthers pink to purple (orange-pink in P. hickmanii).

enclosed in perianth or tip exserted, black, elliptic to ovate, 1.8–2.3 mm, faces subequal, smooth, shiny.

ovate to elliptic or lanceolate, 3-gonous, shiny or dull, smooth, tubercled, or longitudinally reticulate.