Polygonum lapathifolium


Pale Smartweed

Perianth
Regina
06-Aug-2003

Note the distinctive anchor-shaped veins.  The achene has been removed in this photograph.

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Lapathifolium:  Answers to key questions in Budd's Flora and Flora of Alberta leading to this species.  
            This is a variable species.  The pubescence on the leaves can vary from plant to plant, and can disappear as the plant matures.  This specimen is pubescent only on the bottom of the lower leaves.
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plants annual; NOT perennial with extensively creeping rootstocks (BF,FOA)

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plants NOT twining (BF,FOA)

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stem often branched (FOA,BF)

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ocreae not ciliate (BF)

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ocreae entire or merely lacerate or with a fringe of minute bristles; ocreae NOT fringed with coarse bristles (FOA)

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ocreae rarely deeply lacerate (FOA)

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leaves all similar; NOT with long-stalked basal leaves and smaller, stalkless stem leaves (BF)

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leaves chiefly cauline; NOT chiefly basal (FOA)

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leaves NOT jointed at base (FOA)

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leaves large (BF)

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leaves linear, lanceolate, or oblong, cuneate at base; NOT broad, NOT sagittate, NOT hastate, NOT cordate (BF,FOA)

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leaves glabrous below; NOT sparing pubescent (BF)

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leaves white pubescent, glabrous or glandular below (FOA)

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stem commonly with several spike-like racemes (FOA)

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flowers in dense terminal (or axillary) spikes or racemes; flowers NOT solitary, flowers NOT in small axillary clusters; flowers NOT with foliaceous bracts (FOA,BF)

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peduncles and often perianth bearing yellow subsessile glands (BF)

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spikes arching or nodding, slender; spikes NOT erect and NOT thick (FOA)

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flowers pink to whitish; NOT greenish (FOA)

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perianth NOT covered with brownish glands (BF)

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achene 1.5 to 2.0 mm wide; NOT 2.0 to 3.0 mm wide (BF)

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achenes about 2 mm long; NOT 3 mm long (FOA)

 
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Polygonum: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus.
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leaves with ocreae

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flowers in axillary clusters or terminal spike-like racemes; NOT in corymbiform clusters

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flowers NOT in involucrate clusters

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plants WITHOUT a whorl of bracts below flowers

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sepals 5, more or less equal

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stamens 8 or fewer

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stigmas NOT tufted

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seeds generally enclosed by somewhat enlarged calyx, but, if protruding from calyx, the leaves are long and narrow

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embryo at one angle of the lens-shaped or 3-angled achene

 

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Polygonaceae: Answers to key questions in Budd's Flora leading to this family.  These answers will not lead to all genera in Polygonaceae found on the Canadian prairies, but will lead to genus Polygonum
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land plants

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herbs

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plants rooted in soil or water

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plants NOT parasitic on trees

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plants with more than one pair of leaves

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leaves alternate

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leaves with stipules forming a sheath above nodes

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flowers with only one floral ring, with sepals but not petals

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stamens and pistils in each flower