Amaranthus

Love-lies-bleeding Amaranthus caudatus, copyright Tubifex.

Belongs within: Amaranthaceae.

Amaranthus, pigweeds, is a cosmopolitan genus of annual herbs of which some species are cultivated as food plants.

Characters (from Hickman 1993): Annual, monoecious or dioecious. Leaves alternate; blade linear to ovate. Inflorescences borne as cymes in dense, spike-like clusters; bract 1, tip generally short-pointed or -spined, generally scarious; bractlets 0–2. Staminate flowers with sepals 3–5, more or less equal, more or less as bracts; stamens (1–)3–5, filaments free; staminodia absent. Pistillate flowers with sepals (3–)5, more or less equal, scarious excludding midvein, fused at base, falling with fruit; ovary compressed-ovoid, styles (2–)3, stigmas slender, papillate, ovule 1, erect. Fruit circumscissile or indehiscent, smooth or inflated-wrinkled; walls membranous to spongy-hardened. Seed 1, lenticular, smooth, reddish to black.

<==Amaranthus
    |--A. albus Y98
    |--A. arenicola H93
    |--A. blitoides H93
    |--A. brownii O94
    |--A. californicus H93
    |--A. caudatus Linnaeus 1753 K78
    |--A. chlorostachys C55
    |--A. cruentus Linnaeus 1759 K78 (see below for synonymy)
    |    |--A. c. var. cruentus C55
    |    `--A. ‘paniculatus’ var. sanguineus C55
    |--A. deflexus Y98
    |--A. dubius Thell. 1912 K78
    |--A. fimbriatus H93
    |--A. flavus C55
    |--A. graecizans AGF98
    |--A. grandiflorus [=A. mitchellii var. grandiflorus] H90
    |--A. hybridus K78
    |--A. hypochondriacus C55
    |--A. interruptus Brown 1810 [=Euxolus interruptus (Brown) Moq. 1849] K78
    |--A. leptostachyus Benth. 1870 K78
    |--A. lividus Linnaeus 1753 K78 [=Euxolus lividus C55; incl. A. blitum H90]
    |    |--A. l. ssp. lividus K78
    |    `--A. l. ssp. polygonoides K78
    |--A. macrocarpus H90
    |    |--A. m. var. macrocarpus H90
    |    `--A. m. var. pallidus H90
    |--A. mitchellii H90
    |--A. muricatus H90
    |--A. pallidiflorus KM08
    |--A. palmeri H93
    |--A. peniculatus M94
    |--A. powellii H93
    |--A. quitensis K78
    |--A. retroflexus Y98
    |--A. spinosus Linnaeus 1753 K78
    |--A. torreyi H93
    |--A. tricolor Linnaeus 1753 (see below for synonymy) K78
    |--A. tristis C55
    |--A. undulatus LK14
    |--A. viridis Linnaeus 1763 K78 (see below for synonymy)
    `--A. watsonii H93

Amaranthus cruentus Linnaeus 1759 K78 [=A. hybridus ssp. cruentus PP07; incl. A. paniculatus Linnaeus 1763 K78, A. hybridus var. paniculatus (Linnaeus) Uline & Bray 1894 K78]

Amaranthus tricolor Linnaeus 1753 [=A. melancholicus var. tricolor (Linnaeus) Moq. 1849; incl. A. gangeticus Linnaeus 1759, A. melancholicus Linnaeus 1753, A. melancholis f. phyllomanica Sch. & Laut. 1900] K78

Amaranthus viridis Linnaeus 1763 K78 [=Euxolus viridis C55; incl. A. gracilis Desf. 1804 K78, A. spinosus f. inermis Laut. & Sch. 1900 K78]

*Type species of generic name indicated

REFERENCES

[AGF98] Abd El-Ghani, M. M., & A. G. Fahmy. 1998. Composition of and changes in the spontaneous flora of Feiran Oasis, S Sinai, Egypt, in the last 60 years. Willdenowia 28: 123–134.

[C55] Candolle, A. de. 1855. Géographie Botanique Raisonée: Ou exposition des faits principaux et des lois concernant la distribution géographique des plantes de l’époque actuelle vol. 2. Librairie de Victor Masson: Paris.

[H90] Harden, G. J. (ed.) 1990. Flora of New South Wales vol. 1. New South Wales University Press.

[H93] Hickman, J. C. (ed.) 1993. The Jepson Manual: Higher Plants of California. University of California Press: Berkeley (California).

[K78] Kanis, A. 1978. Amaranthaceae. In: Womersley, J. S. (ed.) Handbooks of the Flora of Papua New Guinea vol. 1 pp. 12–42. Melbourne University Press: Carlton South (Australia).

[KM08] Keighery, G. J., & W. Muir. 2008. Vegetation and vascular flora of Faure Island, Shark Bay, Western Australia. Records of the Western Australian Museum Supplement 75: 11–19.

[LK14] Lyons, M. N., G. J. Keighery, L. A. Gibson & T. Handasyde. 2014. Flora and vegetation communities of selected islands off the Kimberley coast of Western Australia. Records of the Western Australian Museum Supplement 81: 205–244.

[M94] May, B. M. 1994. An introduction to the immature stages of Australian Curculionoidea. In: Zimmerman, E. C. Australian Weevils (Coleoptera: Curculionoidea) vol. 2. Brentidae, Eurhynchidae, Apionidae and a chapter on immature stages by Brenda May pp. 365–728. CSIRO Australia.

[O94] Otte, D. 1994. The Crickets of Hawaii: origin, systematics and evolution. The Orthopterists' Society: The Academy of Natural Sciences of Philadelphia.

[PP07] Pandey, R. P., & P. M. Padhye. 2007. Studies on phytodiversity of Arid Machia Safari Park-Kailana in Jodhpur (Rajasthan). Bulletin of the Botanical Survey of India 49: 15–78.

[Y98] Yannitsaros, A. 1998. Additions to the flora of Kithira (Greece) I. Willdenowia 28: 77–94.