sporangiophores's Usage Examples:

In the other Calamarian strobili known the whorls of sporangiophores are separated by whorls of bracts.

Such may be termed sporangiophores.

The stamens of Araucaria and Agathis are peculiar in bearing several long and narrow free pollen-sacs; these may be compared with the sporangiophores of the horsetails (Equisetum); in Taxus (yew) the filament is attached to the centre of a large circular distal expansion, which bears several pollen-sacs on its under surface.

The recently discovered species, Sphenophyllum fertile, while resembling Bowmanites Romeri in its peltate, bisporangiate sporangiophores, is peculiar in the fact that both dorsal and ventral lobes of the sporophyll were fertile, dividing in a palmate manner into several branches, each of which constitutes a sporangiophore.

A, B, Section of Leaf of Potato F, G, H, J, Further development with sporangiophores of Phy- of the sporangia.

The overlapping bracts afforded protection to the sporangia, which were borne on sporangiophores springing from the upper surface of the coherent bracts near their origin from the axis; two sporangiophores usually arose from each bract, and sometimes adhered to its upper surface for some distance.

This similarity is closest in Archaeocalamites, an ancient type found in Upper Devonian rocks; in this the strobilus consists of peltate sporangiophores inserted in whorls on the axis.

That these three sterile segments, with their sporangiophores, are together comparable to one of the bracts of Sphenophyllum, with its sporangiophores, is shown by the vascular supply in each case being derived from a single leaf-trace, So far as is at present known, the Sphenophyllales were homosporous.

In the lax strobili the sporangiophores, which are not peltate, but strap-shaped, were borne, as C.

The spike of Helminthostachys corresponds to that of Ophioglossum, but in it the sporangia are borne on two lateral rows of branched sporangiophores.

The sporangiophores, which are usually half as numerous in each verticil as the bracts, have the same form as in Equisetum, but each bears four sporangia only.

Synonyms:

stem, stalk,

Antonyms:

rear, ride,