Contains 15 accepted taxa overall.
Characteristics
Classification
Citation
AMARANTHUS Linnaeus, Sp. Pl. 989. 1753.
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TYPE: Amaranthus caudatus Linnaeus Lectotypified by Britton & A. Brown, Ill. Fl. N. U.S., ed. 2. 2: 1. 1913.
Species
| Scientific Name | Common Name | Status | Photos |
|---|---|---|---|
| Amaranthus albus | PROSTRATE PIGWEED; TUMBLEWEED | Not Native FACU (NWPL) | |
| Amaranthus australis | SOUTHERN AMARANTH | Native OBL (NWPL) T (WAP) OBL (DEP) | |
| Amaranthus blitum subsp. emarginatus | PURPLE AMARANTH | Not Native | |
| Amaranthus cannabinus | TIDALMARSH AMARANTH | Native OBL (NWPL) OBL (DEP) | |
| Amaranthus caudatus | LOVE-LIES-BLEEDING | Not Native | |
| Amaranthus crassipes | SPREADING AMARANTH | Not Native FAC (NWPL) | |
| Amaranthus deflexus | LARGEFRUIT AMARANTH | Not Native | |
| Amaranthus dubius | SPLEEN AMARANTH | Not Native | |
| Amaranthus floridanus | FLORIDA AMARANTH | Native Endemic OBL (NWPL) OBL (DEP) | |
| Amaranthus hybridus | SLIM AMARANTH; PIGWEED | Not Native | |
| Amaranthus palmeri | PALMER'S PIGWEED; CARELESSWEED | Not Native FACU (NWPL) | |
| Amaranthus polygonoides | TROPICAL AMARANTH | Not Native | |
| Amaranthus retroflexus | RED AMARANTH; ROUGH PIGWEED | Not Native FAC (NWPL) | |
| Amaranthus spinosus | SPINY AMARANTH | Not Native FACU (NWPL) | |
| Amaranthus viridis | SLENDER AMARANTH | Not Native FAC (NWPL) |
[Family identification key]
1. Stem nodes usually with paired spines
1. Stem nodes without spines
2
2. Plant dioecious
3
2. Plant monoecious, staminate and carpellate flowers intermingled or separated
6
3. Leaf blades linear-oblong, <1.1 cm wide, those subtending the inflorescence <0.5 cm wide
3. Leaf blades linear-oblong, lanceolate, to ovate, larger ones >1 cm wide, usually at least some subtending the inflorescence >0.5 cm wide
4
4. Plant (0.25)0.5-1.5(3) m tall; petioles commonly subequal to longer than the leaf blade; staminate flower bracts longer than 2 mm, mostly with prominent midribs; outer staminate tepals with prominent midribs, usually longer than the inner tepals; carpellate flowers with 5 tepals, at least some >2 mm long; utricle circumscissile dehiscent
4. Plant (0.25)1-3(9) m tall; petioles usually shorter than the leaf blade; staminate flower bracts 2 mm or shorter, midribs mostly not prominent or sometimes moderately prominent; outer staminate tepals without prominent midribs (sometimes moderately prominent), mostly not longer than the inner tepals; carpellate flower with 0-2 tepals, tepals usually <2 mm long; utricle indehiscent
5
5. Staminate bracts 1.5-2 mm long, midribs prominent; utricles 1-2.5 mm long; seeds 1-1.2 mm wide
5. Staminate bracts <1 mm long, midribs not prominent; utricles 2.5-4 mm long; seeds 2-3 mm wide
6. Inflorescences predominantly of axillary clusters or glomerules, distal nodes sometimes condensed into leafy spikes
7
6. Inflorescences predominantly terminal spikes and/or panicles, leafless or almost leafless at least in the distal part, axillary spikes or clusters usually also present
10
7. Pistillate flowers usually with 3 tepals
8
7. Pistillate flowers usually with (4-)5 tepals
9
8. Leaf blades obtuse or acuminate to short-mucronate or shallowly emarginate at apex; utricles dehiscent
8. Leaf blades usually deeply and broadly emarginate at apex; utricles indehiscent
9. Inflorescence axes thickened, becoming indurate at maturity
9. Inflorescence axes not thickened, not indurate at maturity
10. Inflorescence bracts shorter than tepals; tepals of pistillate flowers usually 2-3; utricles indehiscent
11
10. Inflorescence bracts usually exceeding tepals, sometimes shorter than tepals; tepals of pistillate flowers usually 5; utricles dehiscent
13
11. Utricles distinctly rugose, equaling or slightly exceeding tepals
11. Utricles smooth to faintly rugose, occasionally wrinkled or rugose in dry plants, distinctly exceeding tepals
12
12. Plants annual; leaf blades usually deeply emarginate at apex; utricles subglobose to obovate, compressed; seeds filling fruit almost completely
12. Plants short-lived perennial or annual; utricles ellipsoid, slightly to distinctly inflated; seeds filling only proximal portions of fruit; leaf blades retuse or shallowly emarginate at apex;
13. Tepals of pistillate flowers acute, acuminate, to aristate at apex
14
13. Tepals of pistillate flowers obtuse, rounded, to emarginate at apex
15
14. Bracts shorter than 2 mm, shorter than tepals; style branches strongly spreading; seeds 0.8-1 mm wide
14. Bracts 2-7 mm, longer than or equaling tepals; style branches erect or slightly reflexed; seeds. 1-1.3 mm wide
15. Inflorescences drooping, usually bright red to purple, occasionally white or yellowish, rarely green; bracts subequal to tepals and usually not exceeding style branches at maturity; seeds white, ivory, reddish, brown, or black
15. Inflorescences erect or reflexed only at the tip, usually green, occasionally silvery green, sometimes reddish; bracts usually exceeding tepals and style branches; seeds brown to black