The ornamental design for a horticulturalluminaire, as shown and described.
FIG. 1 is a perspective view of the new design for a horticultural luminaire as seen from the top, rear, left side;
FIG. 2 is a front elevational view thereof, the rear view being identical;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a right side elevational view thereof; and,
FIG. 6 is a left side elevational view thereof.
The broken line disclosure is for environmental purposes only and does not form a part of the claimed design. The horticultural luminaire is shown with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design.