Flora of North America species comparison

emerging near origin, or growing through cortex and emergent some distance from origin.

on substrate surface.

present or absent, mainly protostelic, in some species becoming actino- or plectostelic, on substrate surface or subterranean, or forming stolons.

present or absent, simple or branched, branching pattern dichotomous and sometimes pseudomonopodial;

leaves uniform or dimorphic or trimorphic.

clustered, mainly unbranched or sparsely branching mainly at base, 1.2–1.6 cm diam.;

annual bud constrictions abrupt and conspicuous.

simple or branched, usually conspicuously leafy at least at base; abscising gemmae formed by reduced lateral shoots.

round or flat in cross section;

leaves on subterranean parts flat, appressed, nonphotosynthetic, and scalelike;

leaves on aerial parts appressed, ascending, or spreading, with 1 central unbranched vein, needlelike to lanceolate to ovate, remote to dense and imbricate, with or without basal and/or mucilage canals.

few and like upright shoots but annual bud constrictions absent.

spreading to reflexed, dark green, linear-lanceolate, (2.5–)5–8 × 0.6–1.2 mm;

margins closely and shallowly dentate mainly in distal 1/2;

apex sharply pointed, lacking hair tip.

solitary, sessile on shoots, 15–30 × 3.5–4.5 mm.

sessile or stalked, upright, nodding, or pendent.

solitary, adaxial near leaf base or axillary; subtending leaves (sporophylls) unmodified and photosynthetic to much modified, nonphotosynthetic, reduced, and aggregated in strobili;

sporangia reniform to globose, thick-walled with hundreds of spores, outer walls variously modified.

all 1 kind, trilete, thick-walled, surfaces pitted to small-grooved, rugulate, or reticulate.

(1.5–)3.5 × 0.7(–2) mm, abruptly narrowed to pointed tip.

subterranean and nonphotosynthetic or surficial and photosynthetic.

= 68.