Amaranths and Pigweeds
Amaranth Family - Amaranthaceae
Love-lies-bleeding Amaranthus caudatusAn ornamental species that is unknown in the wild and is thought to have originated from Amaranthus quitensis. Grown as a garden annual and occasionally occurring self-sown among garden waste. The flowers are typical of the genus in their structure, but they are bright red in colour and are clustered in long, pendulous spikes.
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Common Amaranth Amaranthus retroflexus
Probably native to Central America but commonly introduced throughout much of the world. An upright species to a metre in height, usually with a tight flowerhead and noticeably hairy leaves. Very similar to Green and Indehiscent Amaranths and best told by the tepals, which are clearly rounded, but with a mucronate tip - in other words, the tip of the petal is rounded, but has a hair-like extension of the mid-vein. The tepals also tend to exceed the length of the central ovary of the flower, causing the stigmas to be somewhat hidden within the centre. The seed capsule splits neatly, horizontally across the centre when the seeds are ripe.
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Green Amaranth Amaranthus hybridus
Introduced from the Americas and now a common weed throughout much of the world. An upright species to a metre in height, usually with a somewhat open flowerhead and noticeably hairy leaves. Very similar to Common and Indehiscent Amaranths and best told by the tepals, which are clearly tapered to points at the tip. The tepals are usually about the same length as the central ovary of the flower, causing the stigmas to be somewhat more obvious within the centre. The seed capsule splits neatly, horizontally across the centre when the seeds are ripe. Despite the name, some populations have distinctly reddish-tinged flower spikes.
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Indehiscent Amaranth Amaranthus bouchonii
A plant of uncertain origin, with no known native distribution and perhaps having occurred spontaneously in Europe from Amaranthus powellii. An upright species to two metres in height, usually with a somewhat open flowerhead and noticeably hairy leaves. Very similar to Common and Indehiscent Amaranths with tepals that are clearly tapered to points at the tip. The bracteoles surrounding the flowers are particularly long and sharply-pointed. The seed capsule remains as an entire case surrounding the seed. If rubbed, it breaks roughly and doesn't form a neat, horizontal split across the centre.
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when rubbed |
Slender Amaranth Amaranthus viridis
Native to Central and South America but widely introduced to tropical and warm temperate regions of the world. An upright species to a metre in height (though often much less), typically with a long, slender flower spike. Flowers with 2-3 tepals, which are about as long as the strongly wrinkled fruit (and thus concealing it).
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Prostrate Pigweed Amaranthus blitoides
Native to North America but widespread as an introduction throughout much of the world. A prostrate annual that usually hugs the ground but may grow to 30cm in height among taller vegetation. Leaves usually well marked with a pale blotch. Flowers in small clusters in the leaf axils, often red-tinged. Bracteoles shorter than the tepals, with the four to five tepals being unequal in length.
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White Pigweed Amaranthus albus
Native to southern North America but widely introduced throughout much of the temperate world. A well branched, low-growing species to around 60cm in height. Leaves usually with clearly crinkled or undulate margins. Flowers in small clusters in the leaf axils.
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Perennial Pigweed Amaranthus deflexus
Native to South America but widely introduced to temperate parts of the world. A spreading, procumbent species but young plants can be quite upright initially. Unusual for an Amaranthus in being a perennial species. Quite distinctive in its narrowly diamond-shaped leaves and relatively short, non-spiny flower clusters.
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