The term you want is inflorescence, which refers to the "shoot" or "runner" that emerges from the crown and grows toward the surface, and usually above it. Some species produce inflorescences more readily than others (some rarely if ever do in the aquarium) and the species here, which is Echinodorus grisebachii, var. bleherae, is one that does when the plants are settled and in good health.
Most species in the genus Echinodorus are true amphibious bog or marsh plants. In their habitat, they generally spend half the year emersed (= growing as a normal terrestrial plant in the air with the roots in the damp forest soil) and then submersed during the flood season. Some species that grow in rivers that are open to the sky (thus getting sufficient sunlight) remain permanently submersed. All species grow well submersed, which is why they have become such favoured aquarium plants.
The inflorescence is produced during the emersed cultivation. Along the stalk there are nodes, and these will produce the small white flowers common to the genus, followed of course by seeds. When the plant is grown submersed as in the aquarium, adventitious or daughter plants develop from the nodes, two per node (they initially look like one plant, but as they develop it will be seen that they are in fact two, easily separated). Flowering rarely occurs when the plant is grown permanently submersed, but it sometimes does; I had one E. major that flowered, and this species is not at all prolific with inflorescences.
Sometimes the inflorescence is single, but I frequently see them divide, and I have had some that were even triple. And while one at a time from a plant is usual, I have seen two and even three from the same plant, each appearing a couple weeks apart.
I have seen inflorescences appear after the plant has been transplanted; the one I now have in my 70g sent out two inflorescences about three weeks ago, two weeks after being moved from the old 115g tank. One of these has divided. When left alone, it is usual for the plant to produce inflorescences twice a year. Plants need a period of vegetative rest; in the temperate climates they frequently die down and "hibernate" during the winter. In the tropics they simply have periods of rest (during which new leaves and inflorescences will not appear) between periods of new growth, and usually twice annually.
You can easily see in the photos that your plants are thriving, so you can expect much more of all this.
Byron.
