Editing Conium (section)

== Description ==
Plants of the genus ''Conium'' are eudicots, flowering plants distinguished by their two cotyledons (embryonic leaves) and tricolpate (three-pored) pollen. They are typically biennial, forming basal rosettes in the first year of growth, and sprouting a rigid, hollow flower stalk in the second. Germination occurs between spring and autumn. Occasionally, plants which germinate in early spring are annual instead of biennial.<ref name=":3">{{Cite journal|title=Conium maculatum (poison hemlock)|url=https://www.cabi.org/isc/datasheet/14820|access-date=2020-12-03|website=www.cabi.org|date=2015 |doi=10.1079/cabicompendium.14820 |last1=Parker |first1=Chris |volume=CABI Compendium |page=14820 |doi-access=free }}</ref> These plants grow best in wet, poorly drained areas with nutrient rich soil. They grow well in nitrogen rich soil, and are able to tolerate high levels of heavy metals, such as arsenic, cadmium, and lead. ''Conium'' plants are diploid, with a chromosome number of 2n = 22 (haploid number 11). They grow from one to three meters tall, varying between species. They produce hermaphroditic flowers, which are typically insect pollinated or self-fertilized.<ref name=":4">{{Cite journal|last1=Hotti|first1=Hannu|last2=Rischer|first2=Heiko|date=2017-11-14|title=The killer of Socrates: Coniine and Related Alkaloids in the Plant Kingdom|journal=Molecules|language=en|volume=22|issue=11|pages=1962|doi=10.3390/molecules22111962|issn=1420-3049|pmc=6150177|pmid=29135964|doi-access=free}}</ref>  

=== Stems ===
''Conium'' plants are herbaceous, growing non-woody, hollow, and hairless stems. Generally, the stem is striated and light green; however, the coloring varies by species and variety. Some express purple blotching throughout, some have purple blotching localized near the base, and others have no markings at all.

=== Leaves ===
The alternate leaves are pinnately compound and finely divided, with the exact pinnation patterns varying between species and leaf type. For example, stem leaves of ''C. maculatum'' plants are typically 2-4 pinnate, but basal leaves are 1-3 pinnate. The leaves and petioles are light green. Similar to the stem coloring, some species and varieties express purple blotching on the leaves and petioles.<ref name=":7">{{Cite journal|last=Hilliard|first=O.M.|date=December 1985|title=Conium (Umbelliferae) in southern Africa|journal=[[South African Journal of Botany]]|volume=51|issue=6|pages=465–474|doi=10.1016/S0254-6299(16)31629-5|doi-access=free|bibcode=1985SAJB...51..465H }}</ref>

=== Flowers ===
Terminal inflorescences are made up of many small flowers, colored white, yellow, or green depending on the species. The flowers are grouped together in umbrella shaped umbels. Plants in the genus ''Conium'' have compound umbels, with multiple dome shaped clusters branching out from a central point. Flowers are around 2&nbsp;mm across, and the umbrella shaped umbels range from 1–8&nbsp;cm in diameter.<ref name=":3" />

==== Fruits ====
The two seeded fruit is one of the most significant distinguishing factors between species. They are relatively round, slightly flattened, and dark green or brown. Depending on the species, they range from 2.5 to 4&nbsp;mm long. Some species have distinctive light brown ribs, some have ribs that are noticeably crenulate (scalloped edges), and others show relatively unpronounced rib patterns.<ref name=":5">{{Cite journal|date=2017-01-01|title=Mzansi's mountain hemlocks: The identities of Hilliard and Burtt's Conium species 3 and 4 (Apiaceae) and a revised key for the genus in sub-Saharan Africa|journal=South African Journal of Botany|language=en|volume=108|pages=243–247|doi=10.1016/j.sajb.2016.11.006|issn=0254-6299|last1=Magee|first1=A.R.|last2=Clark|first2=V.R.|doi-access=free|bibcode=2017SAJB..108..243M }}</ref>

==== Seeds ====
Each plant typically produces between 1,700 and 39,000 seeds, and 40-85% will germinate in suitable conditions. However, seeds will remain viable for 3 to 6 years after dispersal. Producing a large number of seeds, and growing in a variety of locations, these plants can be considered invasive in some cases.<ref name=":3" />

=== Chemical composition ===
Poisonous alkaloid compounds are present in all tissues of ''Conium'' plants. As a flower develops into a fruit and matures, the alkaloids present transform from γ-coniceine, to [[coniine]], and finally to [[N-Methylconiine|N-methylconiine]].<ref name=":4" /> When ingested, these compounds interrupt the central nervous system, paralyzing respiratory muscles, and finally resulting in death through respiratory failure.<ref name=":2" />

=== Species differentiation from other plants ===
Members of the genus ''Conium'' can be easily confused with edible plants of the family Apiaceae.<ref>{{Cite web|date=2017-06-26|title=Poisons of the Carnegie: Hemlock|url=https://carnegiemnh.org/poisons-carnegie-hemlock/|access-date=2020-12-03|website=Carnegie Museum of Natural History|language=en-US}}</ref> ''Conium'' plants have leaves similar to [[parsley]] (''Petroselinum crispum'') and roots similar to [[parsnip]] (''Pastinaca sativa''). However, a few characteristics can be used to distinguish the poisonous ''Conium'' plants from other harmless Apiaceae plants.<ref name=":4" /> For example, ''Conium'' leaves and stems release a foul odor when crushed. Additionally, the species ''C. maculatum'' stands out with its purple blotching pattern.<ref>{{Cite web|title=Ohio Weedguide|url=https://www.oardc.ohio-state.edu/weedguide/single_weed.php?id=114|access-date=2020-12-03|website=www.oardc.ohio-state.edu}}</ref>