Will my Rose of Jericho actually bloom?

Yes - if it is a genuine Selaginella lepidophylla, it will open within 4-8 hours of being placed in water. Place it roots-down in a shallow bowl with about half an inch of spring or room-temperature water. If it has not begun to move within 12 hours, try fresh water and make sure the base is in contact with the water, not just resting above it.

How long can I keep it in water?

Keep it in water for no more than 7 days at a time. After that, remove it and allow it to dry completely for at least two weeks before the next cycle. A plant left in standing water indefinitely will develop mold and eventually die. The dormancy period is not optional - it is what keeps the plant alive for years of repeated use.

Is this the same as the biblical Rose of Jericho?

No, and this distinction matters. The biblical plant referenced in scripture is Anastatica hierochuntica, native to the Middle East and North Africa, which must remain rooted in soil to survive. The plant sold in most spiritual shops - including this one - is Selaginella lepidophylla, native to the Chihuahuan Desert of Mexico and the southwestern United States. It is the rootless variety: it can be revived repeatedly with no soil at all, which is the version used in Mexican folk practice and Latin American botanicas. Both are called 'Rose of Jericho.' They are different plants with different behaviors.

Spring water or rainwater is preferred, particularly for ritual work. Tap water works for revival and will not harm the plant, but many practitioners feel filtered or natural water carries cleaner energy for intentional use. If tap is all you have, let it sit out overnight to allow the chlorine to off-gas before using it.