Alstroemeria: volume per stem, and where that volume goes
Count heads rather than stems. Each stem carries an umbel of several blooms that open in turn, so a bunch of seven stems fills a vase the way fifteen single-headed flowers would.
That arithmetic is why alstroemeria sits in every shop.
Where the volume comes from and what it costs
A rose gives you one head at the top of a bare stem, and the outline of a rose bouquet grows by adding stems. Alstroemeria builds outward from each one. Five or six stems already read as a full bunch from across a room. Fifteen becomes genuinely large, and it does that without the price of fifteen roses.
Head size is the trade. Individual blooms are small and marked with fine veins and speckles on the inner petals, so at arm's length the bouquet reads as detailed rather than bold. For an occasion that needs one large head at the front, this flower sits better beside roses or lilies than in place of them.
Colour behaves well in quantity. Because each umbel mixes open and closed buds, even a single-shade bunch holds two or three tones instead of flattening into a block of one colour.
Travel, and the mistake that ruins the shape
Stems are flexible and hollow. Laid flat in a car boot for a few hours, the tips curve upward towards the light. They stay bent once the bunch is stood up, and no amount of arranging afterwards straightens them.
Carry it upright and stand it up again the moment it arrives. Couriers in Almaty use tall boxes for the same reason rather than laying the flowers on their side.
In the room
A wide-mouthed vase suits them. A narrow neck squeezes the umbels together and the outer blooms crease against each other. The bunch loses exactly the airiness that made it worth buying.
They are close to scentless. On a desk, in a hospital room or on a dining table that matters more than it sounds, because a flower nobody has to smell can go anywhere.
Half-closed buds open over several days, which changes how the bunch is judged. On day one it looks modest. By the third or fourth day it is at its fullest, so if the handover is the point, ask for stems that are further along before the bouquet is made.
Keeping it going
Alstroemeria bouquets last around two weeks in clean water, longer than most cut flowers sharing the same table. The limiting factor is foliage: leaves yellow well before the first bloom drops, and a bunch with tired leaves looks finished while the flowers are still fine. Strip the lower third when the stems go in, and pull yellow leaves off as they appear. Spent blooms do not fall on their own, so pinch them out of the umbel at the base. Change the water every couple of days and recut, because a soft hollow stem sours faster than a woody one.