Illicium sp.

Today’s photo of the day features a photograph taken by me, with a write-up from Connor (Connor neglected to mention the sweet fragrance of this as-yet-unidentified species, so I’ll throw that in). Connor writes:

Species of Illicium can be found in both the New and Old World. Native species can be found in both southeast Asia and southeastern North America. The Illiciaceae are contained within the Austrobaileyales, one of the basal angiosperm lineages. The sister group to the Austrobaileyales includes the monocots, eumagnoliids, and eudicots.

In The four-celled female gametophyte of Illicium (Illiciaceae; Austrobaileyales): implications for understanding the origin and early evolution of monocots, eumagnoliids, and eudicots, Williams and Friedman trace the evolution of the female gametophyte through various angiosperm lineages.

The most common female gametophyte, or embryo-sac, in angiosperms is the Polygonum-type. It consists of two synergid cells which attract the growing pollen tubes, and an egg at the micropylar end. At the chalazal end three antipodal cells are present which are thought to function in embryo-sac nutrition. At the centre of the Polygonum-type embryo-sac are two polar nuclei which can fuse to become a binucleate central cell and the triploid (3n) endoserpm upon fertilization.

By examining the four-celled gametophyte found in Illicium, Williams and Friedman hypothesized that this type (also found in another basal angiosperm lineage, Nympheales) is an ancestral feature in the angiosperms. The Polygonum-type and other seven-celled / eight-nucleate embryo-sacs are the product of several modifications to this ancestral type which included the addition of the three antipodal cells and the binucleate central cell. This embryo-sac is a derived character of the monocots, eumagnoliids, and eudicots. Interestingly, the authors note that a seven-celled / eight-nucleate female gametophyte is also found in the most basal angiosperm clade, Amborellaceae. However it does not function in the same way as the similar embryo-sacs found in the higher angiosperms and is thought to be a separate derivation of the seven-celled/ eight-nucleate female gametophyte.

In Developmental evolution of the sexual process in ancient flowering plant lineages (PDF), the same authors provide a thorough description of each embryo-sac development mentioned above along with diagrams.

Illicium sp.

9 responses to “Illicium sp.”

  1. Daniel Mosquin

    I should add – this photograph was taken with my new (since December, but not used enough) camera, the Canon G9.

  2. elizabeth a airhart

    is this a star anise
    lovely happy new camera daniel

  3. Daniel Mosquin

    Elizabeth, it is most certainly a relative of what is called a star-anise. As mentioned in a previous post on the same genus, though, not all can be used as a spice: Illicium anisatum.

  4. Sue in Bremerton WA

    What a neat flower. I am SO glad I took Latin long ago. Otherwise I would hardly understand those technical names. As it is I can figure some of them out, and sort of pass on the ones’ I don’t understand. This is a good thing, though, I’m not complaining. I just wonder of you and your colleagues talk that way all the time. Lovely little flower, it reminds me of some kind of flower my auntie used to raise.

  5. Travis

    I notice the families are different between today’s and Illicium anisatum of March ’06.
    is the family a recent revision?

  6. Daniel Mosquin

    Hi Travis,
    Yes, I think so – at least it appears to me to be that way according to the APG (if you follow the link to the family and look at the URL, you’ll note the URL has Schisandraceae in its anchor tag but links to Illiciaceae).
    Actually, I intended to update last year’s Illicium yesterday, but I suppose I became distracted by something. Will do so now.

  7. Deb

    Oops! Your e-mail sends us to the link for 3/19/2006, not today’s. I didn’t even notice until I started reading the comments on that page!

  8. Daniel Mosquin

    Yes, I updated that entry (the family name, and added the other bits into the new format), and it sent out the notification email. A bit of glitch that I’ll have to figure out how not to do in the future.

  9. Joe

    cool explanation of the lineage. i didnt get to read the full text of the paper, but do you know if anyone has found an 8-cell 8-nucleus gametophyte that doesn’t undergo the nuclear fusion? seems to me like that would be basal to the polygonum types. A “missing link” so to speak.

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