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1 Stem obviously jointed; leaves scale-like, borne in a whorl at each of the distant joints; spores borne in a terminal strobilus with peltate scales |
1 Stem (or rhizome) not jointed; leaves scale-like or larger, but if scale-like not borne in whorls at distant joints; spores borne variously, but if in a terminal strobilus the scales not peltate. |
..2 Leaves linear, grass-like, 1-60 cm long, 20× or more as long as wide. |
....3 Leaves solitary (though often the internodes very short from a thin, creeping rhizome); sporangia borne in a spherical (ca. 3 mm in diameter) sporocarp on a separate branch from the rhizome |
....3 Leaves numerous from a corm or short-creeping rhizome; sporangia either borne in the expanded leaf bases ( Isoetes in ISOETACEAE) or in 2 rows at the tip of the linear fertile leaves ( Schizaea in SCHIZAEACEAE), or in a sub-marginal groove on either side of the midrib ( Vittaria in PTERIDACEAE). |
......4 Leaves straight and stiff, arching, or flaccid, from a 2-3-lobed corm; sporangia borne in the expanded, hyaline leaf bases |
......4 Leaves either straight and stiff or notably spiral-curly, from a short-creeping rhizome; sporangia borne in 2 rows either at the expanded pectinate tip of the fertile leaves or along much of the length of the linear leaves. |
........5 Leaves 10-60 cm long, straight, stiff; plants epiphytic or rarely epipetric, the leaves pendent |
........5 Leaves 1-12 cm long, spiral-curly; plants terrestrial in peaty substrate, the leaves erect |
..2 Leaves various (scale-like, awl-like, moss-like, or flat), but not linear and grass-like, mostly 1-10 (-20)× as long as wide. |
..........6 Leaves inconspicuous, reduced to a few nerveless scales (< 1.5 mm long), the internodes much longer than the leaves; sporangia yellowish, 3-locular, 1-2 mm in diameter; stems upright, repeatedly branched dichotomously |
..........6 Leaves either larger or, if scale-like, with 1 or more nerves and longer than the internodes (the leaves thus overlapping); sporangia yellowish to brownish, 1-locular, < 1 mm in diameter; stems either subterranean or surficial rhizomes or erect or ascending (and sometimes dichotomously branched in whole or in part in Huperzia in HUPERZIACEAE, and Diphasiastrum and Dendrolycopodium in LYCOPODIACEAE). |
............ 7 Plant with leaves very numerous and overlapping along the creeping, ascending, erect, or pendant stems, the leaves scale-like or awl-like, 0.5-2 (-3) mm wide, typically acute, acuminate, or hair-tipped; sporangia either in terminal strobili (axillary to specialized, smaller leaves) or axillary to normal leaves; [Lycophytes]. |
............ ..8 Sporangia borne in flattened or quadrangular strobili sessile at the tips of leafy branches; spores and sporangia each of two sizes, the megasporangia larger and borne basally in the strobili |
............ ..8 Sporangia borne either in the axils of normal foliage leaves, or in strobili sessile at the tips of leafy branches or stalked on specialized branches with fewer and smaller leaves; spores and sporangia each of one size. |
............ ....9 Leafy stems erect or pendant, simple or dichotomously branched, the ultimate branches vertically oriented (upwards or downwards); sporophylls like the sterile leaves or only slightly reduced, in annual bands along the stem; vegetative reproduction by leafy gemmae near the stem apex ( Huperzia) or lacking gemmae ( Phlegmariurus) |
............ ....9 Leafy stems prostrate or erect, if erect then generally branched, the ultimate branches spreading (horizontal) or ascending; sporophylls differing from sterile leaves, either broader and shorter, or more spreading, aggregated into terminal cones; lacking vegetative reproduction by gemmae. |
............ 7 Plant with leaves not as above (see below for details); [Pteridophytes]. |
............ ......10 Leaves palmately lobed. |
............ ........11 Leaves divided into separate sterile and fertile segments, the sterile leaf blade 30-90 cm long, ovate to lanceolate, entire-margined, obtuse, the longer fertile portion with 2 rows of sporangia somewhat imbedded in it |
............ ........11 Leaves with fertile portions in patches near the tips of the lobes |
............ ......10 Leaves unlobed (or if lobed, pinnately so). |
............ ..........12 Plant with 1 (-several) leaves, divided into separate sterile and fertile segments, the sterile leaf blade 0.3-90 cm long, ovate to lanceolate, entire-margined, unlobed, obtuse, the longer fertile portion with 2 rows of sporangia somewhat imbedded in it |
............ ..........12 Plant with many leaves, generally 5 or more, not divided into separate sterile and fertile segments, the leaves either (a) small, 0.3-1.6 cm long, obovate, scattered along a very thin creeping rhizome, or (b) larger, (2-) 8-30 cm long, cordate at base, the tip long-attenuate (often proliferous, bearing a plantlet at the tip). |
............ ............ 13 Leaf blades (2-) 8-30 cm long, cordate at the base, the tip long-attenuate, often proliferous (bearing a plantlet at the tip); sporangia grouped into indusiate sori on the undersurface; leaf texture moderately thick; rhizome erect or ascending, 1.0-1.5 mm in diameter, the leaves clustered from its tip |
............ ............ 13 Leaf blades 0.3-15 cm long, cuneate at the base, acute to rounded or obtuse at the tip, not proliferous; sporangia solitary in a marginal pocket on the leaf; leaf texture very thin; rhizome creeping on the surface of rock or bark, either 0.1-0.3 or 0.5-1.5 mm in diameter, the leaves scattered along it |
............ ............ ..14 Leaf blades 0.3-1.6 cm long; sporangia solitary in a marginal pocket on the leaves; leaf texture very thin; rhizome 0.1-0.3 mm in diameter |
............ ............ ..14 Leaf blades 2-15 cm long; sporangia borne in round sori on the lower surface of the leaves; leaf texture herbaceous to subcoriaceous; rhizome 0.5-1.5 mm in diameter |
1 Leaves thread-like or quill-like, about as thick as wide. |
..2 Plants bulbous at base, and with the leaf bases expanded and containing sporangia; plant tufted or with very short rhizomes; [Lycophytes] |
..2 Plants either somewhat bulbous or not at the base, the leaf-bases not containing sporangia; plant rhizomatous; [Pteridophytes, Eudicots, Monocots]. |
....3 New leaves unfurling with circinate vernation (a fiddlehead); plants reproducing by spores, from sporocarps on short stalks from the rhizome; [Pteridophytes] |
....3 New leaves lacking circinate vernation; plants reproducing by flowers and seeds. |
......4 Perianth differentiated, with either 3 sepals and 3 petals or 5 sepals and 5 petals; stamens either 7-many or stamens 4. |
........5 Sepals 3; petals 3; stamens 7-many; [Monocots] |
........5 Sepals 5; petals 5; stamens 4; [Eudicots] |
......4 Perianth undifferentiated, with 0, 3, or 6 tepals; stamens 1, 2, or 3; [Monocots]. |
..........6 Gynoecium of 2 or more pistils, each pistil with 1 carpel and with 1 stigma |
..........6 Gynoecium of 1 pistil, each pistil with (2-) 3 carpels and (2-) 3 stigmas. |
............ 7 Fruit an achene; perianth absent |
............ 7 Fruit a capsule; perianth of 6 tepals |
1 Leaves ribbon-like or strap-like, distinctly flattened (sometimes only near the tip of the leaf). |
............ ..8 Subterranean portions of plant bearing bladder-traps; flowers yellow or purple, bilaterally symmetrical |
............ ..8 Subterranean portions of plant lacking bladder traps; flowers white, green, gray, radially symmetrical (except bilaterally symmetrical in Glossostigma in PHRYMACEAE). |
............ ....9 Leaves broadened towards the tip; [Monocots, Eudicots]. |
............ ......10 Flowers 3-merous; [Monocots] |
............ ......10 Flowers 4- or 5-merous; [Eudicots]. |
............ ........11 Leaves phyllodial, with obvious cross-partitions (septa); leaves alternate |
............ ........11 Leaves not phyllodial; leaves opposite |
............ ....9 Leaves parallel-margined or tapering towards the apex over much of their length; [Monocots]. |
............ ..........12 Leaves tapering towards the apex over much of their length; plant either tufted and not rhizomatous, or short rhizomatous;. |
............ ............ 13 Plant tufted, not rhizomatous; leaves spreading radially; inflorescence a tightly button-like head of very numerous small flowers, white, gray, tan, yellowish, or blackish; roots thickened, septate (not requiring magnification), unbranched |
............ ............ 13 Planted short-rhizomatous; leaves distichous, equitant; inflorescence either a subglobular, ovoid, or cylindrical head, of spirally imbricate scales, or a diffuse corymb; roots not thickened, not septate, branched. |
............ ............ ..14 Inflorescence a diffuse corymb; rhizomes and roots bright red |
............ ............ ..14 Inflorescence a subglobular, ovoid, or cylindrical head of spirally imbricate scales subtending individual flowers; rhizomes and roots not bright red |
............ ..........12 Leaves parallel-margined; plant usually rhizomatous. |
............ ............ ....15 Plants of marine habitats, growing submersed in salt water; [FL and the Gulf Coast of AL, MS, and LA] |
............ ............ ....15 Plants of freshwater or slightly to somewhat brackish habitats; [collectively widespread]. |
............ ............ ......16 Leaves lacking any midvein; flowers and fruits in globose heads |
............ ............ ......16 Leaves with a midvein; flowers and fruits solitary or in diffuse inflorescences. |
............ ............ ........17 Leaves with a distinct, broad lacunar band along the midvein |
............ ............ ........17 Leaves lacking a distinct lacunar band along the midvein. |
............ ............ ..........18 Stamens 3 |
............ ............ ..........18 Stamens >6 |