Equisetum telmateia 巨問荊

Common name: Great Horsetail
Scientific name: Equisetum telmateia 巨問荊
Genus: Equisetum 木賊屬
Family: Equisetaceae 木賊科, horsetail family

Origin: native

Date: 26th April (cones on non-photosynthetic shoots) & 27th June (vegetative shoots) on different locations.

[334_1] Fertile stems (non-photosynthetic shoots) separate in spring, can grow up to 25 cm.

[349] Newly fertile stem shoot with cone at the top already.

[349_1] Young hexagonal sporangiophore and green sporangia underside.

[340] Cone 4-8 cm, are borne on non-photosynthetic shoots.

[350] Another fertile shoot with bending.

[336] Young cone, with sporangia mature started from the bottom.

[338] An older cone.

[339] Older sporangiophore were found near the base of the cone.

[347]

The enlarged photo of the bottom end of the strobilus (cone) 孢子葉穗, 孢子葉球 showing the thick central strobilus axis (Sa) (cone axis). There is a ring-like outgrowth present below the strobilus, which is called annulus (As). Some thought that it is the uppermost whorl of sterile leaves while others thought that is is the lowermost sterile sporangiophore.

[336_2] Younger sporangiophore are found at the top of the cone.

[336_1] Sporangiophore found at the middle of the cone.

[336_3]

[339_2] Enlarged photo showing the structure of the sporangiophore. Each sporangiophore has a stalk (St) to attach to the thick central asix known as strobilus axis (cone axis). The free end of the sporangiophore is a hezagonal peltate disc (Pd). Many sporangia (singular - sporangium, Sg) are attached on the undersurface of the Pd.

[339_1] Side view of an sporangiophore 孢子囊托, 孢(子)囊柄 (outlined in red).

[337_1] Fly is attracted to the sporangium.

[347_1] The oldest sporangiophores are found near the base of the cone.

[341] Internode and stem sheath of the fertile shoot.

[342_cropped] Swollen stem sheath of the fertile shoot, with dark, fine-pointed teeth.

[346] Dying out fertile stem (probably last year stem).

[352] Vegetative shoot? starting emerging from the soil.

[352_1] Stem sheath of the young vegetative shoot?

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The following photos were taken on 27th Jun on another location. All are vegetative shoots now.

[094] A robust deciduous perennial, can grow up to 2 m. This is the largest British horsetail.

[081] Stem about 1 cm diameter at base.

[062] Richly branched to top of stem.

[066]

[066_1] Stem internodes ivory white until autumn, with 20-40 fine ridges (the ridges are very unclear indeed).

[066_2] Stem sheath with 20-30 teeth. Teeth dark, fine-pointed, to 10 mm.

[067] Branches at the node with stem sheath. Note the branch segments have slightly black, tipped teeth.

[090_1] Underside of the node showing the point of branching.

[071] Side branches.

[071] slightly black, tipped teeth of the side branches. Note the branches are angular.

[096_1] The tip of the side branch, with tipped teeth.

[073] The uppermost of the stem showing the gradual change of the stem sheaths.

[077] The uppermost of the stem of another individual showing the gradual change of the stem sheaths.

[087] Stem cross-section.