Your help is appreciated.    We depend on donations to help keep this site free and up to date for you. Can you please help us?


See list of 12 species in this genus

References: Bassett (1973), Rahn (1996).

  • 1a. Leaf blades dentate to 1- or 2-times pinnately lobed; corolla pubescent on the abaxial 
(i.e., outer) surface; spike nodding prior to anthesis
  • 1b. Leaf blades usually entire (sometimes with obscure teeth); corolla glabrous on the abaxial surface or pubescent in P. maritima; spike not nodding prior to anthesis
    • 2a. Leaves borne on a stem, opposite, the blades linear and 1–3 mm wide [Fig. 774]; peduncles arising from the axils of leaves [Fig. 774]
    • 2b. Leaves all basal, the blades linear to ovate and 1–110 mm wide [Fig. 774]; peduncles arising among basal rosettes of leaves [Fig. 775]
      • 3a. Bracts and/or sepals conspicuously pubescent; plants monocarpic, usually annual (sometimes biennial)
        • 4a. Plants subdioecious; lobes of the corolla of carpel-bearing, chasmogamous flowers erect after anthesis, connivent, closing over the fruit; leaf blades oblanceolate to obovate
        • 4b. Plants synoecious; lobes of the corolla spreading to reflexed after anthesis; leaf blades linear to narrow-oblong
          • 5a. Bracts conspicuously exceeding the flowers and fruits, the lower ones 8–45 mm long, mostly 4–10 times as long as the sepals [Fig. 775]; leaf blades sparsely villous to nearly glabrous on the adaxial surface; inflorescence sparsely tomentose
          • 5b. Bracts inconspicuous, scarcely, if at all, extending beyond the flowers and fruits, 2–5.4 mm long, mostly 1–3 times as long as the sepals; leaf blades evidently villous-tomentose on the adaxial surface; inflorescence evidently tomentose
      • 3b. Bracts and sepals glabrous or ciliate only on the apical portion of the keel; plants polycarpic, perennial (monocarpic and annual in P. pusilla)
        • 6a. Flowers with 2 stamens; corolla lobes 0.25–0.5 mm long; plants annual
        • 6b. Flowers with 4 stamens; corolla lobes 0.7–2.5 mm long; plants perennial
          • 7a. Leaf blades linear, 1–12 mm wide, fleshy; corolla tube pubescent on the abaxial surface; plants of tidal wetlands and Atlantic coast shorelines
          • 7b. Leaf blades narrow-elliptic to broad-ovate or obovate, 6–110 mm wide, herbaceous to somewhat fleshy; corolla tube glabrous on the abaxial surface; plants of upland habitats, often weedy (of saline shores in P. intermedia)
            • 8a. Bracts and sepals conspicuously keeled; lobes of the corolla 0.7–1 mm long; pyxis 4- to 34-seeded; all the roots slender and filamentous; spikes 5–30 cm tall
              • 9a. Pyxis (3–) 4–6 mm tall, circumscissile near the base, containing 4–9 (–10) seeds; bracts narrow-triangular; seeds 1.5–2 (–2.5) mm long, not reticulate-patterned; petiole usually anthocyanic near the base
              • 9b. Pyxis (2–) 2.5–4 mm tall, circumscissile near the middle, containing 6–22 (–34) seeds; bracts broad-ovate; seeds 1–1.7 mm long, reticulate-patterned; petiole usually green near the base (but sometimes anthocyanic in P. major)
                • 10a. Pyxis rounded to pointed at the apex, containing (4–) 6–11 (–13) seeds; leaf blades membranaceous to fleshy-herbaceous, glabrous or pubescent, broad-elliptic to broad-ovate, borne on relatively more elongate and slender petioles; plants of primarily inland habitats, casually found bordering saline communities
                • 10b. Pyxis broadly rounded at the apex, containing 14–34 seeds; leaf blades subcoriaceous-fleshy, usually pubescent, narrow-elliptic to ovate, borne on broad, short petioles; plants of saline shores and near coastal habitats
            • 8b. Bracts and sepals flat or slightly keeled; lobes of the corolla 1.5–2.5 mm long; pyxis 2- to 4-seeded; primary roots prominently thickened, tuberous near junction with foliage; spikes 1.5–10 cm tall
              • 11a. Calyx apparently composed of 3 sepals, 1 of the sepals with 2 midveins and formed by fusion of 2 sepals; leaf blades lanceolate to narrow-elliptic, ascending; scape prominently furrowed
              • 11b. Calyx composed of 4 distinct sepals; leaf blades elliptic to ovate or obovate, prostrate; scape not furrowed

Show All Couplets

 Show photos of:   Each photo represents one species in this genus.