1. Spore Shedding Vascular Plants
Psilotum
Lycopodium
Equisetum

2. Psilotum nudum (whisk fern)

3. Psilotum nudum (whisk fern)

4. Psilotum has a stem doing virtually all the photosynthesis, with dichotomous branching, enations without vascular tissue, and yellow synangia in the axils of the enations.
Below ground, the stem is not photosynthetic but the epidermis forms rhizoids for anchorage.
The plant thus lacks roots and leaves with underground stem (rhizome) doing the anchorage functions.

5. Psilotum stem cross section
radial
exarch
triarch
actinostele
cutin
guard cells
epidermis
PSN cortex
lignified cortex
respiring cortex
phloem
metaxylem
protoxylem

6. Protosteles: haplosteles actinostele plectostele Siphonosteles:
cortex phloem xylem
Siphonosteles:
siphonostele
solenostele
dictyostele
cortex phloem xylem pith
leaf gap
leaf trace
eustele
atactostele
dicot stem
monocot stem

7. Psilotum stem specimen more than triarch

8. Psilotum rhizomes with rhizoids

9. Psilotum rhizome cross-section

10. Psilotum stem demonstrates dichotomous branching, enations (no vascular tissue) and two of the three sporangia in a single synangium

11. Psilotum sporangium (a three-parted synangium)
This specimen has shed its spores into the wind and so the sterile jackets are empty.
At the bottom of the view is a partial stem cross-section showing: epidermis, cortex and a portion of the vascular cylinder.

12. Psilotum gametophyte tissues all haploid
antheridia
Psilotum gametophyte tissues all haploid
archegonium

13. Psilotum gametophyte (SE to NW) and sporophyte (Y-shape)
The photo is flipped and cropped. Some versions of Powerpoint may fail to retain this making the labels erroneous!
1N gametophyte
1N antheridium
2N rhizome
2N rhizoid
1N rhizoid

14. Cooksonia
Rhynia
Earliest Land Plants
from the
Early Devonian