Angiosperms (Flowering Plants) • Earth.com

Tall Jointweed

(Polygonella gracilis)

galery
en

Description

Herbs, annual, dioecious, 8-16 dm. Stems erect, simple or branched proximally and distally, glabrous. Leaves mostly fuga--ceous; ocrea margins not ciliate; blade filiform to broadly spatulate or, rarely, obovate, (9-)19-39(-65) - 0.8-5(-8) mm, base attenuate, margins not hyaline, apex obtuse, glabrous. Inflorescences (13-)20-40(-70) mm; ocreola encircling rachis, only the base adnate to rachis, apex acute. Pedicels spreading in anthesis, sharply reflexed in fruit, 0.1-0.3 mm, as long as subtending ocreola. Flowers functionally unisexual; filaments dimorphic; anthers deep red; styles and stigmas less than 0.1 mm in anthesis. Staminate flowers: outer tepals loosely appressed in anthesis and fruit, white, elliptic, 1.1-2 mm in anthesis, margins entire; inner tepals loosely appressed in anthesis and fruit, white, elliptic, 1-2 mm in anthesis, margins entire. Pistillate flowers: outer tepals loosely appressed in anthesis, usually spreading in fruit, white to pink, often drying red and streaked or dotted orange or brown, elliptic to oblong, 0.8-1.4 mm in anthesis, margins entire or obscurely erose; inner tepals loosely appressed in anthesis and fruit, white to pink, often drying yellow, broadly elliptic to ovate, 1.8-3.6 mm in flower, margins entire or obscurely erose. Achenes included or exserted, reddish brown to yellow-brown, (2-)3-gonous, 2-3.4 - 1-1.4 mm, shiny, smooth. 2n = 22, 24.Flowering Aug-Nov. Pinelands, sandhills, sandy roadsides; 0-60 m; Ala., Fla., Ga., Miss., N.C., S.C.

Taxonomic tree:

Domain:
Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Order:Caryophyllales
Family:Polygonaceae
Genus:Polygonella
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