Editing Chondrus crispus (section)

== Description ==
''Chondrus crispus'' is a relatively small sea alga, reaching up to a little more than {{convert|20|cm|frac=4}} in length. It grows from a discoid [[holdfast (biology)|holdfast]] and branches four or five times in a dichotomous, fan-like manner. The morphology is highly variable, especially the broadness of the thalli. The branches are 2–15&nbsp;mm broad and firm in texture, and the color ranges from bright green towards the surface of the water, to deep red at greater depths.<ref>{{cite book |last1=Sadava |first1=David |last2=Heller |first2=Craig |last3=Orians |first3=Gordon |last4=Purves |first4=Bill |last5=Hillis |first5=David |title=Life: The Science of Biology |date=2008 |publisher=Sinauer Associates |location=Sunderland, MA |isbn=9780716776710 |page=601 |edition=8th}}</ref> The [[gametophyte]]s (see below) often show a blue [[iridescence]] at the tip of the fronds<ref>{{cite journal|last1=Chandler|first1=Chris J.|last2=Wilts|first2=Bodo D.|last3=Vignolini|first3=Silvia|last4=Brodie|first4=Juliet|last5=Steiner|first5=Ullrich|last6=Rudall|first6=Paula J.|last7=Glover|first7=Beverley J.|last8=Gregory|first8=Thomas|last9=Walker|first9=Rachel H.|title=Structural colour in Chondrus crispus|journal=Scientific Reports|date=3 July 2015|volume=5|pages=11645|doi=10.1038/srep11645|pmid=26139470|pmc=5155586|bibcode=2015NatSR...511645C}}</ref> and fertile sporophytes show a spotty pattern. ''[[Mastocarpus stellatus]]'' (Stackhouse) Guiry is a similar species which can be readily distinguished by its strongly channelled and often somewhat twisted thalli.

Irish moss undergoes an [[alternation of generation]] lifecycle common in many species of algae. The two distinct stages are the sexual [[haploid]] [[gametophyte]] stage and the asexual [[diploid]] [[sporophyte]] stage. In addition, a third stage – the [[carposporophyte]] – is formed on the female gametophyte after fertilization. The male and female gametophytes produce gametes which fuse to form a diploid carposporophyte, which forms [[carpospore]]s, which develops into the sporophyte. The sporophyte then undergoes [[meiosis]] to produce haploid tetraspores (which can be male or female) that develop into gametophytes. The three stages (male, female, and sporophyte) are difficult to distinguish when they are not fertile; however, the gametophytes often show a blue iridescence.

{{gallery|mode=packed
|Life cycle Chondrus.jpg|Lifecycle of ''C.&nbsp;crispus'': Below the life stages are indicated if the life stage is [[haploid]](n) or [[diploid]] (2n) and the type of [[carrageenan]] present.
|Chondrus crispus.jpg|How the lifecycles of ''C.&nbsp;crispus'' might look in nature: The [[gametophyte]]s show blue iridescence and the fertile [[sporophyte]]s exhibit a spotty pattern.
|Haeckel Florideae Chondrus crispus.png|Illustration from ''[[Kunstformen der Natur]]'' (1904)
|Cultured Chondrus.jpg|Laboratory-grown specimen displaying high symmetry.
}}