#gnetophytes

These Questions are the result of suggestions from the previous iteration.

This category may include suggestions made too late to fall into the correct grouping.

Please add new suggestions below if you have them for future consideration.

I can't remember if we did this one. It would have been late last summer. i think we did some specific species, but i can't remember if it was done in total. I am quoting the whole suggestion here: "Carboniferous forests, before Angiosperms became dominant. I want to see the lepidodendrons and the huge equisetes and all the many Araucaria and gnetophytes and ginkgos that once thrived."

1.1 Gnetum

Pantropical distribution. 3 Clades apparently reflect geography (Asia, Africa, S.America) and a recent (Cenozoic) radiation.

Raw species diversity goes Asia > S.America > Africa. Africa only 2 sp. limited to west coast tropics.

Absent from mainland Australia, but can be found on offshore islands.

Form = woody vines, but 2 sp. are trees (G.gnemon + G.costatum). Tree growth habit is nested within Asia clade, therefore a secondarily derived form.

G.gnemon specifics

Reportedly insect pollinated but exacts unclear. On male trees, the sterile/undeveloped female organs apparently used to lure insects with some secretion.

Seeds will develop without fertilization (Gingko also does this), hence not easily known if a seed is viable (unless you dissect for embryo).

Generalist for light/soil condition

Long germination time (4+ months)

Hence planting recommendation = sow in bulk and forget (lmao).

1.2 Ephedra

Dryland specialists, core of diversity in Old World. Forms continuum from dry parts of Africa (North + East) - Mediterranean - Steppes. Eastern limit in Old World = Korea + Siberia. Pockets in North America (Dry South) and South America (limited to Andes). Well known group, nothing new to add.

1.3 Welwitschia

The renown Fog Desert specialist from South-West Africa. Single species group, but Angola-Namibia types might be different. Signature 2-leaf appearance apparently due to apex aborting after 2 leaf stage, though deformities are common (3+ leaf individuals).

Undergoing horticulture craze. Thai growers doing mass production, including aberrant morphs (multileaved) or variegated types. Prices has gone from $100s to $1000s.

German botanic gardens have long cultivation history (due to colonial history)

Surprisingly, grows readily in wet tropics. Deep rooted and reportedly very water hungry (even in humid climates) but must drain/dry well (non-negotiable). Standing water tray okay for watering.

2.1 Gnetophytes in Deep Time

Long pollen record (End Perm - Present). Welwitschia-Ephedra pollen very distinct in fossil record, bears deep grooves from front-back axis (superficially like rugby ball). Large diversification around ~100 Mya but crash after Meszoic. The 3 extant groups are deeply diverged but apparently the specific anatomy/ecology is very modern.

Gnetum does not have clear fossil record. But reportedly shares some reproductive anatomy with Bennettitales.

Seeds are 2 layered (Welwitschia-Ephedra have only 1).

Female reproductive opening composed of radial arranged cell layer.

Gnetum reproductive organ likely derived from whole axis. It is a compound structure (eg. Asteraceae).

Ephedra californica (by flora-file)

The skinny blue stem/leaves of this plant create striking vertical texture in the garden. The genus ephedra is in the plant division known as gnetophyta, and produces cones instead of fruit. This genus is considered very old and is taxonomically placed with the gymnosperms such as conifers, cycads, and gingkoes.

Many plants in this genus contain the chemicals ephedrine and pseudoephedrine, and have long been used in traditional medicines for their stimulant and decongestive properties. It is such a strong stimulant that Ephedra is considered a banned substance by the International Olympic Committee and the World Anti-Doping Agency. Some  American species were used to make a strong and stimulating beverage by Native Americans and Mormon pioneers, which led to the common names of Indian Tea and Mormon Tea.

Ephedra sinica has been used in traditional Chinese medicine since at least 5000 BC, and some reports suggest it has been used medicinally much longer than that. In Chinese Medicine it is known as ma huang, which translates literally to 'cannabis yellow'.