Annual or perennial herbs, or tall woody bamboos. Flowering stems (culms) jointed, internodes hollow or solid; branches arising singly from nodes and subtended by a leaf sheath and 2-keeled prophyll, often fascicled in bamboos. Leaves arranged alternately in 2 ranks, differentiated into sheath, blade, and an adaxial erect appendage at sheath/blade junction (ligule) ; leaf sheath surrounding and supporting culm-internode, split to base or infrequently tubular with partially or completely fused margins, modified with reduced blade in bamboos (culm sheaths) ; leaf blades divergent, usually long, narrow and flat, but varying from inrolled and filiform to ovate, veins parallel, sometimes with cross-connecting veinlets (especially in bamboos) ; ligule membranous or a line of hairs. Inflorescence terminal or axillary, an open, contracted, or spikelike panicle, or composed of lax to spikelike racemes arranged along an elongate central axis, or digitate, paired, or occasionally solitary; axillary inflorescences often many, subtended by spatheoles (specialized bladeless leaf sheaths) and gathered into a leafy compound panicle; spikelets often aggregated into complex clusters in bamboos. Spikelets composed of distichous bracts arranged along a slender axis (rachilla) ; typically 2 lowest bracts (glumes) empty, subtending 1 to many florets; glumes often poorly differentiated from accompanying bracts in bamboos. Florets composed of 2 opposing bracts enclosing a single small flower, outer bract (lemma) clasping the more delicate, usually 2-keeled inner bract (palea) ; base of floret often with thickened prolongation articulated with rachilla (callus) ; lemma often with apical or dorsal bristle (awn), glumes also sometimes awned. Flowers bisexual or unisexual; lodicules (small scales representing perianth) 2, rarely 3 or absent, 3 to many in bamboos, hyaline or fleshy; stamens 3 rarely 1, 2, 6, or more in some bamboos, hypogynous, filaments capillary, anthers versatile; ovary 1-celled, styles (1 or) 2(rarely 3), free or united at base, topped by feathery stigmas, exserted from sides or apex of floret. Fruit normally a dry indehiscent caryopsis with thin pericarp firmly adherent to seed, pericarp rarely free, fleshy in some bamboos; embryo small or large; hilum punctate to linear.
About 700 genera and 11,000 species: widely distributed in all regions of the world.[1]
There are approximately 65 species, subspecies, varieties, forms, and cultivars in this genus: P. alpina · P. alpinum (Alpine Timothy) · P. alpinum alpinum · P. alpinum commutatum · P. alpinum rhaeticum · P. alpinum trabutii · P. alpinuma · P. alpinun · P. ambiguum · P. arcticum · P. arenarium (Sand Timothy) · P. asperum · P. autumnale · P. bertoloni · P. bertolonii (Diploid Timothy) · P. boehmeri · P. bohmeri · P. bohneri · P. boissieri · P. brachystachyum · P. bulbosum · P. corsicum · P. crypsoides · P. crypsoideum · P. dentatum · P. echinatum · P. exaratum · P. exaratum aegaeum · P. exaratum exaratum · P. flavum · P. geniculatum · P. gibbum · P. graecum (Ballast Timothy) · P. graecum aegaeum · P. graecum graecum · P. himalaicum · P. hirsutum · P. hubbardii · P. michelii · P. montanum · P. montanum montanum · P. montanum serrulatum · P. paniculatum (British Timothy) · P. phalaroideum · P. phleoides · P. phleoiides · P. prantensis · P. pratense (Cats Tail) · P. pratense 'Aureum' · P. pratense 'Comer' · P. pratense bertolonii · P. pratense nodosum · P. pratense pratense (Common Timothy) · P. pratense serotinum · P. pretense · P. rhaeticum · P. sardoum · P. schoenoides · P. serrulatum · P. strictum · P. subulatum (Italian Timothy) · P. subulatum ciliatum · P. subulatum subulatum · P. tenue · P. viride
There are approximately 465 species, subspecies, varieties, forms, and cultivars in this genus. Here are just 100 of them: H. × hybridus (Hybrid Hellebore) · H. × hybridus 'Blue Metallic Lady' (Blue Metallic Lady Lenten Rose) · H. × hybridus 'Spotted Lady' (Spotted Lady Lenten Rose) · H. × hybridus 'Yellow Lady' (Yellow Lady Lenten Rose) · H. 'Andrey Glyn' · H. 'Bloash' · H. 'Brandywine Hybrids' (Brandywine Lenten Rose) · H. 'Briar Rose' · H. 'Christmas Lantern' · H. 'Citron' · H. 'Green Dragon' · H. 'Jebb's White' · H. 'Magical Black' · H. 'Meerea Park' · H. 'Moonshine' · H. 'Party Dress Group' (Hellebore) · H. 'Picotee' (Hellebore) · H. 'Pink Beauty' (Pink Beauty Lenten Rose) · H. 'Pink Ice' · H. 'Royal Heritage Strain' (Hellebore) · H. 'Sappho' · H. 'Sirius' · H. 'Sparkling Red' · H. 'White Beauty' · H. 'Winter Joy Bouquet' · H. abchasicus · H. abschasicus · H. acutifolius · H. albus · H. antiquorum · H. argutifolius (Corsican Hellebore) · H. argutifolius 'Janet Starnes' (Corsican Rose) · H. argutifolius 'Little 'Erbert' · H. argutifolius 'Pacific Frost' (Speckled Corsican Hellebore) · H. argutifolius 'Silver Lace' (Corsican Hellebore) · H. argutifolius corsicus (Corsican Hellebore) · H. argutifolius hybrid · H. argutifolius large flowered · H. argutifolius mottled-leaved · H. atrorubens · H. atrorubens 'Spotted Fern' · H. bocconei · H. bocconei bocconei · H. bocconei siculus · H. casta-diva koshiri · H. caucasicus · H. colchicus · H. corsicus · H. croaticus (Croatian Hellebore) · H. cyclophyllus (Hellebore) · H. dumentorum · H. dumentorum atrorubens · H. dumetorum · H. dumetorum atrorubens · H. dumetorum dumetorum · H. ericsmithii 'Sunmarble' (Hellebore) · H. foetidum · H. foetidus (Bear's Foot Hellebore) · H. foetidus 'Bowles' Cabbage Stalk' · H. foetidus 'Chedglow Variegated' · H. foetidus 'Chedglow' · H. foetidus 'Curio' · H. foetidus 'Frenchy' (Bears Foot) · H. foetidus 'Geddington Mist' · H. foetidus 'Gold Bullion' · H. foetidus 'Green Giant' · H. foetidus 'Marlene' (Bears Foot) · H. foetidus 'Melle' · H. foetidus 'Miss Jekyll's Scented' · H. foetidus 'Pewter' · H. foetidus 'Piccadilly' (Piccadilly Lenten Rose) · H. foetidus 'Pontarlier' · H. foetidus 'Red Silver' (Bears Foot) · H. foetidus 'Ruth' · H. foetidus 'Sienna' · H. foetidus 'Silvertooth' (Bears Foot) · H. foetidus 'Sopron' (Bears Foot) · H. foetidus 'Tros-os-Montes' (Bears Foot) · H. foetidus 'Wester Flisk' (Bears Foot) · H. foetidus 'Yorkley' · H. foetidus Bowles' form · H. foetidus compact · H. foetidus gold leaved · H. foetidus Kurt's strain · H. foetidus scented · H. foetidus Wester Flisk Group · H. foetious · H. fortidus · H. guttatus · H. hybridus (Lenten Rose) · H. intermedius · H. lividus (Helleborus) · H. lividus carsicus · H. lividus corsicus var. corsicus · H. lividus dwarf · H. lividus lividus · H. lividus var. serratifolius · H. Marion White Group · H. mosaic virus · H. multifidus (Hellebore)
What is this? Click to find out...