plant terrestrial or on rock . stem compact or short - creeping, horizontal, solenostelic having phloem on both sides of xylem or dictyostelic having complex nets of xylem, clothed with orange to reddish brown hairs . leaf erect rarely forming a flat rosette, partially to entirely dimorphic . sporangium in 2 rows on ultimate segments of fertile pinnae, sessile, oblong; annulus apical . spore tetrahedral - globose, with parallel or rarely anastomosing ridges . gametophyte terrestrial, green, cordate with unequal lobes .

tree shrubs, rarely woody vines, deciduous or evergreen, with aromatic bark, leaves, and flowers . pith septate to diaphragmed . leaf alternate, simple, without stipules, petiolate . leaf blade pinnately veined, unlobed, margins entire . inflorescence axillary to leaf scars on old wood or to leaves on new shoots, solitary flowers or few - flowered fascicles, pedunculate; bract or bracteoles present or absent . flower bisexual, rarely unisexual, ; receptacle becoming enlarged, elevated or flat ; perianth hypogynous, segments valvate or imbricate ; sepal persistent, 2 - 3 - 4, distinct or basally connate ; petal either 6 in 2 unequal whorls of 3 with petals of outer whorl larger, petals of inner whorl fleshier than the outer, often with corrugate nectary zone, or petals 6 - 12 - 15, nearly equal or unequal, veins impressed on inner face ; stamen 10 - 20 or very numerous, hypogynous, spirally arranged, forming ball or flat - topped mass ; filament short, stout ; anther linear to oblong - linear, extrorse, longitudinally dehiscent connective apically elongate, connivent; pistil 1 - many, superior, 1 - carpellate, 1 - locular, distinct or connate to various degrees with at least stigmas distinct ; placentation marginal placenta 1 ; ovule 1 - many per pistil ; style short, thick ; stigma terminal . fruit berries, distinct, 1 - 8 - 12 per flower, or coalescent, forming syncarps 1 per flower . seed 1 - many per pistil, arillate; endosperm ruminate, oily .

tree shrubs, or vines, rarely subshrubs or herbs, with latex or rarely watery juice . leaf simple, opposite, rarely whorled or alternate, pinnately veined, stipules absent or rarely present . inflorescence cymose, terminal or axillary, with bracteoles . flower bisexual, 5 - or 4 - merous, actinomorphic . calyx 5 - or rarely 4 - partite, quincuncial, basal glands usually present . corolla 5 - or rarely 4 - lobed, salverform, funnelform, urceolate, or rarely rotate, lobes overlapping to right or left, rarely valvate . stamen 5 or rarely 4 filament short anther mostly sagittate, free or connivent into a cone adherent to pistil head, dehiscing longitudinally, base rounded, cordate, sagittate, or prolonged into an empty spur pollen granular disc ringlike or cup - shaped, 2 - 5 - lobed, or absent . ovary superior, rarely half - inferior, connate or distinct 1 - or 2 - locular; ovule 1 or 2 - numerous per locule . style 1pistil head capitate, conical, or lampshade - shaped, base stigmatic apex 2 - cleft and not stigmatic . fruit a berry, drupe, capsule, or follicle . seed with or without coma; endosperm thick and often horny, scanty, sometimes absent ; embryo straight or nearly so, cotyledons often large, radicle terete .

tree evergreen, dioecious or monoecious, with relatively large pith in trunk and resin in cortex . leaf spirally arranged or decussate, sessile, decurrent . cone unisexual . pollen cone axillary or terminal on branchlets, solitary or clustered, microsporophylls numerous, spirally arranged, sessile, microsporangia 4 - 20, external, suspended, arranged in 2 rows, filiform ; pollen sac split longitudinally ; pollen nonsaccate . seed cone solitary, terminal on branchlets maturing in 2 nd or 3 rd year; bract numerous, spirally arranged ; ovulate scale degenerate or ligulate connate with bracts on 1 side each with 1 ovule at base abaxially ; ovule connate with ovulate scales or with bracts when ovulate scales degenerate ; bract of mature cones deciduous, flattened, woody or thickly leathery, bearing 1 seed in basal part if developed, sometimes adnate with ligulate seed scales in center of adaxial surface, apex triangular or caudate . seed connate with bracts or detached, flattened, winged or not . chromosome 26 .

herb or lianas shrubs, rarely trees, deciduous or evergreen, often aromatic . wood with broad medullary rays . leaf alternate, simple, petiolate . leaf blade unlobed, margins entire . inflorescence terminal or axillary, racemes or solitary flowers, rarely fan - shaped cymes . flower bisexual; calyx enlarged, petaloid, usually tubular, 1 -, 3 -, 6 -, rarely 5 - merous, lobes valvate ; corolla usually reduced to scales or absent ; stamen 5, 6, or 12 multiples of 3 or 5, free or adnate to styles and stigmas, forming gynostemium ; anther extrorse ; pistil 1 4 - 6 - carpellate ; ovary inferior, partly inferior, or superior ; placentation axile and ovaries 4 - 6 - locular or parietal ; ovule many per locule, anatropous . fruit capsule follicles, regularly to irregularly loculicidal, rarely indehiscent septicidal . seed often flattened; endosperm copious .

herb shrubs, or rarely treelike, with milky or, less often, clear latex . leaf simple, opposite or occasionally whorled, very rarely alternate, usually without obvious stipules, margin nearly always entire . inflorescence terminal, axillary, or extra - axillary, cymose, often condensed and umbel - like, occasionally a racemelike bostrychium . flower bisexual, 5 - merous, actinomorphic . sepal joined at base only often with 5 or more basal glands in the sinuses . corolla sympetalous, reflexed to urceolate or salverform; lobe valvate or overlapping in bud to right or left . corona usually present, inserted on corolla, stamens, or both . stamen 5, usually inserted at base of corolla tube and adhering to stigma head to form gynostegium ; filament usually connate to form a tube enclosing ovaries ; anther 4 - celled Periplocoideae and Secamonoideae or 2 - celled Asclepiadoideae, often with a membranous apical appendage ; pollen tetrad contained loosely on a spatulate translator with a basal corpusculum Periplocoideae, or pollen united into waxy pollinia, each attached through a caudicle stalk to the retinaculum gland between adjacent anthers to form a pollinarium pollinia 2 Asclepiadoideae or 4 Secamonoideae per pollinarium . ovary 2, free, superior; ovule numerous . style connate; stigma head fleshy . fruit of 1 or 2 follicles . seed numerous, strongly compressed, with a coma a prominent basal tuft of silky hairs . chromosome number x = 8 - 11 or 12 .

plant terrestrial, on rock, or rarely epiphytic . stem erect or nearly erect, rarely long - creeping, scaly . stele radially symmetric or dorsiventral with structurally distinct abaxial and adaxial aspects dictyosteles . leaf monomorphic, rarely almost dimorphic with fertile leaves taller and more erect than sterile ones . petiole with 1 vascular bundle X - shaped in cross section or with 2 vascular bundles back to back and C - shaped . blade extremely diverse, simple to 4 - pinnate, commonly with tiny glandular hairs and a few linear scales, rarely with spreading hairs . vein free to anastomosing . sorus borne on veins, ± lunate to linear . indusium usually present shape conforming to sorus and originating along 1 side of sorus . sporangium with stalk of 1 row of cells, annulus vertical, interrupted by sporangial stalk . spore monolete, perispore typically winged, spiny, reticulate, or perforate . gametophyte surficial, green, cordate .

plant aquatic, floating on placid water, occasionally stranded, subsisting on mud; plant heterosporous producing 2 kinds of spores, leptosporangiate, proliferous by axillary fragmentation . root translucent to brown, lax, singular in bundles without branches, emerging at stem branch points; root hair to 1 cm, emerging from root cap . stem usually not green, with extensive subdichotomous branching, prostrate and reniform or polyreniform, or nearly erect . leaf sessile, alternate, often imbricate, in 2 ranks along upper side of stem, 0.6--2 mm wide, ; each leaf with 2 lobes upper emersed lobe greenish or reddish and photosynthetic, with narrow colorless margin, several cells thick, bearing colony of blue - green algae Anabaena in ovoid cavity at base of lower side; low lobe often floating or immersed, slightly larger than upper lobe, mostly not green often colorless and translucent, 1 cell thick except at base, ± cup - shaped . sporocarp in pairs tetrads at base of lateral branches, members of pair of same sex or of different sexes . wn megasporocarps containing 1 megasporangium that produces 1 functional megaspore, megaspore spheric, 0.2--0.6 mm, topped with dark, conic slightly narrower structure indusium covering 3 9 floats and a blue - green algal colony . wn microsporocarps globose, apically umbonate, 10--27 µ m diameter, containing to 130 microsporangia, wn microsporangia containing 32 or 64 microspores 3 µ m diameter aggregated into 3--10 masses covered with arrowlike barbs glabrous or with needlelike hairs on 1 side

herb or shrubs trees, perennial, evergreen or deciduous, sometimes rhizomatous . stem with or without spines . leaf alternate, opposite, or fascicled, simple, 2 - 3 - foliolate, or 1 - 3 - pinnately or 2 - 3 - 4 - ternately compound, stipules present or absent, venation pinnate or palmate . inflorescence terminal or axillary, racemes, cymes, umbels or umbel - like, spikes, or panicles, or flowers solitary or in pairs, flowers pedicellate or sessile . flower bisexual, inconspicuous or showy, radially symmetric ; stipitate gland absent except in Vancouveria ; sepaloid bracteole 0 - 9 ; perianth sometimes absent Achlys, more frequently present, 2 - or 3 - merous, or sepals and petals intergrading Nandis ; sepal 6, distinct, often petaloid and colored, not spurred ; petal 6 - 9, distinct, plane or hooded ; nectary present ; stamen 6 ; anther dehiscing by valves or longitudinal slits ; ovary superior apparently 1 - carpellate ; placentation marginal or appearing basal ; style present or absent, sometimes persistent in fruit as beak . fruit follicles, berries, or utricles . seed 1 - 50, sometimes arillate ; endosperm abundant ; embryo large or small ; mature seed elevated on elongating stalk in Caulophyllum .

plant small to medium - sized, 1 ヨ 2 ヨ 3 cm high, brown, purple - red to black, in dense tufts or in cushions . stem erect to ascending, single or branched without a well - developed central strand . leaf imbricate, often closely appressed when dry, erect - spreading to spreading when moist, lanceolate to ovate or panduriform, mostly concave, with obtuse or acute apices, ; margin plane or incurved ; costa absent or single non - Chinese taxa upper laminal cells small, subquadrate to short - rectangular, irregularly thick - walled, often papillose, basal laminal cells elongate, strongly and irregularly thick - walled, more or less pitted, sometimes cells near margins subquadrate or short - rectangular . wn dioicous or autoicous, perichaetial leaf mostly larger than upper stem leaves, sheathing and convolute, oblong - ligulate, obtuse to acuminate . pseudopodium produced by elongation of gametophytic axis, brown to dark brown . capsule erect, mostly exserted, ovate to ovate - oblong vertically splitting into 4 ヨ 5 valves from the apex to the middle of capsules or to the base when mature . wn calyptrae small, mitrate, spore brown, tetrahedral, papillose . wn protonemata thalloid

tree or shrubs deciduous, monoecious . wn stipules present, free, often deciduous, rarely persistentleaf alternate, simple, petiolate, usually doubly serrate, rarely simply serrate, lobulate, or entire; vein pinnate . flower unisexual . male inflorescence precocious, elongate, pendulous, with numerous overlapping bracts ; each bract usually subtending a small dichasium with 1 - 3 male flowers ; stamen as many as and opposite sepals or, if sepals obsolete then stamens of inflorescence to 20 ; filament very short, connate or nearly so ; anther 2 - loculed, thecae connate or separate, opening by longitudinal slits . female inflorescence pendulous or erect, with numerous overlapping bracts ; each bract subtending a small dichasium with 2 or 3 flowers ; calyx with 1 - 6 scalelike lobes, or obsolete ; petal absent ; ovary inferior 2 - loculed ; style 2, free ; ovule 2, or 1 by abortion, pendulous from near apex of each locule . fruit a nut or nutlet, winged or not . seed 1, with straight embryo and flat or thickened cotyledons, without endosperm .