1 Leaves serrulate, at least at the apex (use 10× magnification); seeds with 2-4 transverse ridges WHICH TAXA BELOW 1A have smooth seeds?

  2 Leaves and stems glabrous.

    3 Seeds with 3-4 (-6) prominent transverse ridges that interrupt abaxial keel; cyathia gland red to purple (sometimes yellow on older cyathia); stems prostrate; [s. IN and c. TN westward, primarily w. of MS river]

    3 Seeds with faint ridges, not interrupting abaxial keel; cyathia gland green, brown, or yellow to pink (lacking a darkened red or purple coloration).

      4 Stems erect to ascending (the tips not drooping)

      4 Stems prostrate to ascending, drooping at tips or plants mat-forming.

        5 Staminate flowers 2-5; seeds 0.9-1.0 mm long, minutely beaded with 3-4 transerve ridges that do not interrupt abaxial keel; [coastal LA and TX only]

        5 Staminate flowers 5-20; seeds 1.0-1.4 mm long, smooth, dimpled, or rugose; [scattered in our area, widespread in w. US]

  2 Leaves and stems variously pubescent.

          6 Ovaries and capsule glabrous.

             7 Stipule connate on both sides of stems.

               8 Stipule irregularly lacerate, ca. 0.5 mm long (sometimes to 1.0 mm); stems erect to ascending, the hair (at least sparsely) pilose proximally and glabrous distally; seeds with 2-3 prominent transverse ridges, sometimes reticulate-pitted; [native SC s. to FL, w. through TX; waif northwards]

               8 Stipule triangular, or laciniate-subulate into filiform segment; stems prostrate or erect to ascending, the hair usually spreading hirsute, strigillose or pilose (not just proximally); seeds rugulose, sometimes also bearing low transverse ridges; [VA w. to IL northward]

             7 Stipule distinct (or only basally connate on one side of the stem in E. nutans).

                 9 Leaf blade surfaces papillate, often also with at least some long thin hair; cocci of capsule often elongated, distally empty; [TX]

                 9 Leaf blade surfaces not papillate, pilose, villous, sericeous, or glabrous; cocci of capsule not elongated nor distally empty; [collectively widespread].

                   10 Stipule usually distinct, sometimes connate on one side of stem; capsule 1.9-2.3 mm long; stems ascending or suberect, puberulent when young; adaxial surface of leaf blade often red-mottled; [widespread throughout our area]

                   10 Stipule distinct or connate (if connate, on both sides of stem); capsule 1.4-1.8 mm long; stems prostrate or widely spreading, spreading-hirsute [VA w. to IL northward]

          6 Ovaries and capsule variously pubescent.

                     11 Stipule connate (sometimes only on one side of the stem).

                       12 Stems erect to ascending.

                          13 Stipule usually distinct, rarely connate at base, if divided the segment deltate to linear-subulate; capsule and ovaries with whitish hair; staminate flowers 2-8; seeds 0.7-0.9 mm long, usually rugulose or with 3-6 low transverse ridges; [widespread]

                          13 Stipule distinct when young, connate into a deltate scale when older, erose or laciniate with dark gland at the base or along the margin; capsule and ovaries with yellowish hair; staminate flowers 15-25; seeds 1.2-1.3 mm long, with 3-5 shallow depressions separated by low, inconspicuous ridges; [c. and s. FL only]

                       12 Stems prostrate.

                            14 Capsule with conspicuous glabrous areas between pubescent keel.

                              15 Seeds smooth or with faint transverse ridges, reddish-brown, orange, or grayish-pink colored; plant pubescence variously sericeous, pilose, or villous; staminate flowers 6-15; [s. FL only]

                              15 Seeds with sharp transverse ridges, white with concealed brown color beneath the seed surface; plant pubescence crisped-villous; staminate flowers 3-6; [widespread, including s. FL]

                            14 Capsule uniformly pubescent, not with conspicuous glabrous areas between keel.

                                16 Style unbranched

                                16 Style 2-fid.

                                  17 Capsule strigose to sericeous; involucral gland appendage unequal; staminate flowers 3-5; [LA and FL]

                                  17 Capsule pilose to villous; involucral gland appendage ± equal in size (or absent); staminate flowers 8-12; [s. TX]

                     11 Stipule distinct.

                                    18 Style unbranched

                                    18 Style 2-fid.

                                       19 Capsule usually glabrous between pubescent keel (the pubescence most conspicuous only on the keel).

                                         20 Seeds smooth or with faint transverse ridges, reddish-brown, orange, or grayish-pink colored; plant pubescence variously sericeous, pilose, or villous; staminate flowers 6-15; [s. FL only]

                                         20 Seeds with sharp transverse ridges, white with concealed brown color beneath the seed surface; plant pubescence crisped-villous; staminate flowers 3-6; [widespread, including s. FL]

                                       19 Capsule uniformly pubescent, not with conspicuous glabrous areas between keel.

                                           21 Cyathia clustered, or in dichotomously branched axillary inflorescence. [THIS CHARACTER NEEDS VALIDATION OR RE-WORDING, TEST IN HERBARIUM]

                                             22 Gland appendage absent

                                             22 Gland appendage present (the petaloid portion of the cyathia, distal to the gland).

                                               23 Plants with coarse pubescence, the stem trichome consisting of larger yellow and smaller white types; stipule usually distinct, rarely connate at base (if divided the segment deltate to linear-subulate); gland appendage sometimes absent or diminuitive; staminate flowers 2-8; seeds 0.7-0.9 mm long, usually rugulose or with 3-6 low transverse ridges; [widespread]

                                               23 Plants with fine pubescence, the stem trichome only of one white type; stipule distinct when young, connate into a deltate scale when older, erose or laciniate with dark gland at the base or along the margin; gland appendage present; staminate flowers 15-25; seeds 1.2-1.3 mm long, with 3-5 shallow depressions separated by low, inconspicuous ridges; [c. and s. FL only]

                                           21 Cyathia solitary in the leaf axil, or in reduced unbranched axillary inflorescence. [THIS CHARACTER NEEDS VALIDATION OR RE-WORDING, TEST IN HERBARIUM]

                                                 24 Gland appendage (the petaloid portion of the cyathia) conspicuously unequal in length, at least one or two shorter than the remaining appendage; plants mat-forming (E. thymifolia) or not (only occasionally in E. pergamena); [FL].

                                                    25 Plants mat-forming, stems prostate only; gland elliptic; ovary densely strigose; staminate flowers 3-5; [disturbed uplands]

                                                    25 Plants not mat-forming (only occasionally in E. pergamena), stems prostate to ascending; gland lunate (crescent-shaped) or reniform (kidney-shaped); ovary puberulent, sericeous, or pilose; staminate flowers 5-15; [intact sites, occasionally disturbed].

                                                      26 Plants annual with taproot, the stems 10-45 cm long, pilose; leaves sometimes revolute; capsule pilose; seeds orange-brown, glaucous; staminate flowers 5-8; [pine rocklands, marl prairie, or disturbed uplands]

                                                 24 Gland appendage ± equal in length; plants usually mat-forming; [collectively widespread, including FL].

                                                        27 Plants perennial with strongly thickened and lignified roostocks; staminate flowers 8-12; [s. TX only]

                                                        27 Plants annual with taproot (or sometimes taprooted perennials in E. thymifolia); staminate flowers 2-5; [collectively widespread in our area].

                                                          28 Middle node of stems forming adventitious root (slowly pull up some of the stems to see if rooted in soil)

                                                          28 Stems not forming adventitious root (stems merely lying flat).

                                                            29 Leaves serrulate (on the longer leaf margin) or subentire; seeds 1.0-1.2 mm long; style clavate; [widespread]

                                                            29 Leaves (the larger ones at least) usually conspicuously serrate, smaller leaves serrulate; seeds 0.7-0.9 mm long; style slender; [FL]

1 Leaves absolutely entire; seeds smooth, variously rugose or wrinkled, or bearing 2-4+ distinct transverse ridges.

                                                              30 Stems and leaves variously pubescent, at least on the upper stem surface (except E. deltoidea ssp. deltoidea, which can be pubescent to glabrous on both sides).

                                                                 31 Capsule with glabrous areas between the pubescent keel; plants annual; [s. TX]

                                                                 31 Capsule uniformly pubescent throughout (sparsely pubescent to glabrous in E. deltoidea ssp. deltoidea, but lacking the conspicuous contrast between keel and inter-keel space described above); plants perennial; [widespread, including TX].

                                                                   32 Distal leaves linear to elliptic-linear; [TX]

                                                                   32 Distal leaves not consistently and conspicuously linear (instead elliptic to ovate); [widespread, including TX]

                                                                     33 Stems erect to ascending.

                                                                       34 Stipule filiform; [OK and TX westward]

                                                                       34 Stipule triangular or subulate; [s. FL].

                                                                         35 Gland appendage ± equal in length; stem pubescence on both upper and lower stem surfaces.

                                                                           36 Stipule pilose; stems not wiry, 1-3 mm in diameter

                                                                           36 Stipule villous-hirsute; stems wiry, < 1 mm in diameter.

                                                                              37 Stem and capsule pubescence villous with uncinate or irregularly twisted hair, 0.2-0.5 mm long

                                                                              37 Stem and capsule pubescence villous-hirsute with straight, spreading hair, 0.6-0.7 mm long

                                                                     33 Stems prostrate or decumbent.

                                                                                38 Stipule filiform; [OK and TX westward]

                                                                                38 Stipule triangular or subulate; [s. FL or s. TX].

                                                                                  39 Capsule canescent; gland purple-black; the appendage absent or forming narrow rim around distal margin of gland; [s. TX]

                                                                                  39 Capsule glabrous or variously pubescent (canescent in E. deltoidea ssp. serpyllum); gland green to yellow-green or pinkish colored; the appendage either absent, forming a narrow ring, or present; [s. FL]

                                                                                    40 Gland appendage ± equal in length; gland green to yellow-green.

                                                                                      41 Leaves and stems glabrous or sparsely pubescent

                                                                                      41 Leaves and stems canescent or villous.

                                                                                        42 Stem and capsule pubescence villous with uncinate or irregularly twisted hair, 0.2-0.5 mm long

                                                                                        42 Stem and capsule pubescence canescent with appressed hair, < 0.1 mm long

                                                              30 Stems and leaves glabrous (on both sides).

                                                                                           43 Stipule connate, forming a conspicuous scale-like structure; stems frequently rooting at the node.

                                                                                             44 Leaf margin whitish; plants perennial, with a moderately to strongly thickened rootstock; [TX westward]

                                                                                             44 Leaf margin green; plants annual, or sometimes perennial with a slightly thickened rootstock (E. blodgettii); [widespread, including TX].

                                                                                               45 Gland red, the appendage unequal in length; cyathia solitary, in cymose clusters distally on stem, or in congested axillary branches; [peninsular FL]

                                                                                               45 Gland yellow, the appendage uniformly equal in length; [widespread]

                                                                                           43 Stipule distinct, not merging to form a singular scale-like structure; stems rooting or not.

                                                                                                 46 Seeds 1.6-2.4 mm long; [OK and TX westward]

                                                                                                 46 Seeds 0.8-1.4 mm long; [collectively widespread].

                                                                                                   47 Cyathia solitary at distal node, the distal node not also bearing small cymose clusters.

                                                                                                     48 Stems prostrate, plants herbaceous, sometimes mat-forming.

                                                                                                        49 Leaf blade oblong to oblong-elliptic, 2.6-7.6 mm wide; involucral gland yellowish-pink, 0.3-0.5 mm long, the gland appendage 1.1-1.5 mm long; seeds 1.8-2.1 mm long

                                                                                                        49 Leaf blade narrowly elliptic to lanceolate, 1-2 mm wide; involucral gland slightly stipitate, ca. 0.1 mm long (rudimentary), the gland appendage 0.1-0.2 mm long; seeds 1.0-1.3 mm long

                                                                                                     48 Stems erect to ascending, plants herbaceous or subshrub, not mat-forming.

                                                                                                          50 Plants subshrub or small shrubs, conspicuously woody; [coastal habitats, FL]

                                                                                                          50 Plants herbaceous, sometimes slightly woody at base or with a thickened root stock but plants not obviously subshrub or shrubs; [s. TX or s. FL]

                                                                                                            51 Leaf blade surfaces papillate, often also with at least some long thin hair; cocci of capsule often elongated, distally empty; [s. TX]

                                                                                                            51 Leaf blade surfaces not papillate, usually glabrous or nearly so; cocci of capsule not elongated or distally empty; [s. FL].

                                                                                                              52 Leaves (2.2-) 3.0-6.0 (-8.3)× longer than wide, narrowly lanceolate to linear elliptic, 1-veined; [s. FL mainland only]

                                                                                                              52 Leaves 0.01–3.0 (-3.5)× longer than wide, ovate to lanceolate, 1–3-veined; [s. FL mainland or FL keys]

                                                                                                                53 Leaf apex acute; cyathia gland and appendage length 0.4-0.6 mm total; [FL keys only]

                                                                                                                53 Leaf apex obtuse to rounded; cyathia gland and appendage length 0.6-1.0 mm total; [s. FL mainland only]

                                                                                                   47 Cyathia solitary, or often in small cymose clusters at distal node.

                                                                                                                  54 Mature seeds bluntly 3-4 angled in cross-section, 0.9-1.4 (-1.7) mm long (except E. missurica, with seeds 1.5-2.0 mm long, but with leaves conspicuously linear); leaves fleshy or not.

                                                                                                                     55 Leaves linear (at least distally); seeds 1.5-2.0 mm long

                                                                                                                     55 Leaves oblong, ovate or elliptic; seeds 0.9-1.4 (-1.7) mm long.

                                                                                                                       56 Seeds gray to reddish brown, 0.9-1.1 mm long; leaf base asymmetric but lacking expanded round auricle; [FL]

                                                                                                                       56 Seeds ashy white with a brown longitudinal line on adaxial surface, 1.1-1.4 (-1.7) mm long; leaf base angled or rounded, with one side of the leaf base often expanded into a small rounded auricle; [s. IL to TX, westward]

                                                                                                                  54 Mature seeds rounded in cross section, (1.3-) 1.5-2.6 mm long; leaves often somewhat fleshy; [coastal only, barrier island dune and other sandy coastal habitats].

                                                                                                                         57 Mature seeds (1.3-) 1.5-1.9 mm long; style 0.2–0.3 mm; [preferring habitat behind foredune, VA s. to FL, w. to TX]

                                                                                                                         57 Mature seeds (2.0-) 2.2-2.6 mm long; style 0.7–1 mm; [preferring pioneer habitat in front of foredune and along upper beach areas, FL Atlantic n. to Long Island in our area]