Travel by pollen from Zizania texana (Texas wild rice) was studied in outdoor cement raceways at the San Marcos National Fish Hatchery and Technology Center, San Marcos, Texas. We examined effects of panicle density and distance from a pollen source on abundance of pollen. There were significantly more pollen grains on traps when panicle number was >40 than there were with fewer panicles. More pollen was on traps within 0.75 m of panicles releasing pollen. We examined the timing of release of pollen by Z. texana by collecting pollen at 6-h intervals for four consecutive 24-h periods. Pollen also was collected at 1-h intervals for four 24-h periods. More pollen was trapped 2400–0600 h (nighttime), compared with 0600–2400 h (daytime); peak hourly release of pollen was 0200–0500 h.