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• Papaveraceae
• Argemone
• Argemone mexicana

Argemone mexicana — Mexican prickly-poppy

Facts

Mexican prickly-poppy is an exotic, annual plant known from Connecticut, Massachusetts and Vermont. Although considered native in some portions of its North American range, its status is a source of confusion, and it can be weedy in places. Unlike its cousin, the white prickly-poppy (Argemone albiflora), which has white blooms, this poppy produces orange-yellow flowers. Like its congener, it has prickly, tough leaves. When viewed close up, its highly patterned, rounded seeds are gorgeous. But beware, they are poisonous!

Habitat

Anthropogenic (man-made or disturbed habitats)

Characteristics

• Clonal plantlets

  Bulbils

  the plant does not appear to have bulbils

  Bulblets replace flowers

  there are no bulblets where the flowers are located

• Flowers

  Anther spurs

  the anthers do not have spurs on them

  Carpels fused

  the carpels are fused to one another

  Cleistogamous flowers

  there are no cleistogamous flowers on the plan

  Corolla palate

  no

  Corona lobe length

  0 mm

  Epicalyx

  the flower does not have an epicalyx

  Epicalyx number of parts

  0

  Flower description

  the flower has a superior ovary, and lacks a hypanthium

  Flower petal color

  yellow

  Flower reproductive parts

  the flower has both pollen- and seed-producing parts

  Flower symmetry

  there are two or more ways to evenly divide the flower (the flower is radially symmetrical)

  Flowers sunken into stem

  no

  Form of style

  the style is unbranched, but it has two or more narrow appendages that are part of the stigma

  Fusion of sepals and petals

  • both the petals and sepals are separate and not fused
  • the petals or the sepals are fused into a cup or tube

  Horns in hoods (Asclepias)

  NA

  Hypanthium

  the flower does not have a hypanthium

  Inner tepals (Rumex)

  NA

  Nectar spur

  the flower has no nectar spurs

  Number of carpels

  3–7

  Number of pistils

  1

  Number of sepals, petals or tepals

  there are five petals, sepals, or tepals in the flower

  Number of styles

  1

  Ovary position

  the ovary is above the point of petal and/or sepal attachment

  Petal and sepal arrangement

  the flower includes two cycles of petal- or sepal-like structures

  Petal and sepal colors

  yellow

  Petal appearance

  the petals are thin and delicate, and pigmented (colored other than green or brown)

  Petal folding in bud

  the petals in bud are crumpled erratically

  Petal hairs (Viola)

  NA

  Petal nectaries

  the petals do not have nectaries

  Petal number

  4–6

  Petal tips (Cuscuta)

  NA

  Scales inside corolla

  no

  Sepal and petal color

  the sepals are different from the petals

  Sepal appendages

  the sepals do not have appendages on them

  Sepal appendages (Oenothera)

  NA

  Sepal features

  • one or more sepals have a horn-like (hardened) appendage
  • one or more sepals have a spine at the tip

  Sepal number

  2–3

  Stamen attachment

  the stamens are not attached to the petals or tepals

  Stamen number

  13 or more

  Stamen position relative to petals

  NA

  Stamens fused

  the stamens are not attached to one another

  Staminodes

  there are no staminodes on the flower

  Stigma position

  the stigmas are positioned at the tip of the style

  Style petal-like

  the styles are not petal-like

  Umbel flower reproductive parts

  NA

  Upper lip of bilabiate corolla

  NA

• Fruits or seeds

  Achene relative orientation

  NA

  Achene shape

  NA

  Achene surface (Polygonum)

  NA

  Achene type

  NA

  Berry color

  NA

  Capsule color (Viola)

  NA

  Fruit (pyxis) dehiscence

  NA

  Fruit features (Brassicaceae)

  NA

  Fruit length

  24–45 mm

  Fruit locules

  one

  Fruit shape

  • the fruit is ellipsoid (widest in the middle and tapering to each end)
  • the fruit is obloid (longer than wide and with rounded ends)

  Fruit type (general)

  the fruit is dry and splits open when ripe

  Fruit type (specific)

  the fruit is a capsule (splits along two or more seams, apical teeth or pores when dry, to release two or more seeds)

  Legumes (Fabaceae)

  NA

  Mericarp length

  0 mm

  Mericarp segment shape (Desmodium)

  NA

  Other markings on berry

  NA

  Ovary stipe

  the ovary or fruit does not have a stipe

  Placenta arrangement

  the plant has parietal placentation, where ovules develop on the wall or slight outgrowths of the wall forming broken partitions within a compound ovary

  Rows of seeds in fruit (Brassicaceae)

  NA

  Schizocarpic fruit compression

  NA

  Schizocarpic fruit segments

  0

  Septum in fruit (Brassicaceae)

  NA

  Wings on fruit

  the fruit does not have wings on it

  prickles on fruits

  the fruits are armed with thorns-like defensive structures

• Glands or sap

  Glands on leaf blade

  the leaf blades do not have glandular dots or scales

  Sap

  the sap is milky and opaque, and may be white or colored

  Sap color

  the sap is clear

• Growth form

  Growth form

  the plant is an herb (it has self-supporting stems)

  Lifespan

  the plant lives only a single year or less

  Parasitism

  the plant is not parasitic

  Plant color

  the leaves or young stems of the plant are green

  Spines on plant

  there are spines on the plant

  Underground organs

  there is a thickened taproot on the plant

• Leaves

  Bracteole number (Apiaceae)

  0

  Bracts in plantain (Plantago)

  NA

  Final leaf segment length (compound lvs only)

  0 mm

  Floral bracts

  the flower has one or more bracts associated with it

  Hairs on underside of leaf

  the underside of the leaf is not hairy, or it has very few hairs

  Hairs on upper side of leaf

  the upper side of the leaf is not hairy, or it has very few hairs

  Leaf arrangement

  alternate: there is one leaf per node along the stem

  Leaf blade base

  the leaf has no stalk

  Leaf blade base shape

  the base of the leaf blade is cuneate (wedge-shaped, tapers to the base with relatively straight, converging edges), or narrow

  Leaf blade edges

  • the edge of the leaf blade has lobes, or it has both teeth and lobes
  • the edge of the leaf blade has teeth

  Leaf blade length

  70–200 mm

  Leaf blade shape

  • the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
  • the leaf blade is obovate (egg-shaped, but with the widest point above the middle of the leaf blade)

  Leaf blade surface colors

  the upper side of the leaf blade has obvious spots, mottles or stripes

  Leaf blade width

  Up to 130 mm

  Leaf duration

  the leaves drop off in winter (or they whither but persist on the plant)

  Leaf form

  the leaves are green, with an expanded blade and a leaf-like texture

  Leaf spines

  there are spines along the leaf edges

  Leaf stalk

  the leaves have no leaf stalks, but attach directly to the stem

  Leaf teeth and lobes

  • the leaf blade margin has outward-pointing teeth
  • the leaf has a row of two or more lobes on each side of the central axis

  Leaf type

  the leaves are simple (lobed or unlobed but not separated into leaflets)

  Leaf variation

  the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem

  Leaves per node

  there is one leaf per node along the stem

  Specific leaf type

  the leaves are simple (lobed or unlobed but not separated into leaflets)

  Stipule features

  NA

  Stipules

  there are no stipules on the plant

• Place

  Habitat

  terrestrial

  New England state

  • Connecticut
  • Massachusetts
  • Vermont

  Specific habitat

  man-made or disturbed habitats

• Stem, shoot, branch

  Branched tendrils

  NA

  Hair between stem nodes

  the stem has no hairs between the nodes

  Hairs between stem nodes

  the stem has no hairs between the nodes

  Plant height

  Up to 80 cm

  Tendril origin

  NA

  Tendrils

  the plant does not have tendrils

Wetland status

Not classified

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae