Flowers of the woody vine Pachyptera hymenaea change from dark lavender to light lavender or white in three days while retained on plants. By the time flowers are three days old, they do not contain pollen or nectar, but may attract pollinators to the plants. Thrips and weevils preyed upon reproductive parts of P. hymenaea. Ants and bees foraged upon its nectar, and bees collected its pollen. Pachyptera hymenaea (DC.) A. Gentry is a woody, high-climbing vine native from southern Mexico to southeastern Brazil (Gentry 1974b). This vine was called Pseudocalymma alliaceum (Lam.) Sandwith as well as many other names (Gentry 1973, 1974b; Williams 1973). It bears funnelform, about 5 cm long flowers which vary from white to lavender (Standley 1938). Its leaflets, stems, and flowers have a strong garlic-like odor; hence, locally this plant is known as "bejuco de ajo" (garlic vine) (Standley and Steyermark 1947). Observations were made during one week in midFebruary in Santa Rosa National Park, Guanacaste Province, Costa Rica. Ten large flower buds and 10 dark lavender and light lavender or white flowers were examined for nectar and pollen at 0600 (dawn), 0900, 1200, 1500, and 1800 (dusk) on a dry, clear day, making a total of 150 flowers and buds. The flowers were not numerous enough for larger samples. In the study of floral maturation, I tagged individual buds and flowers. The presence of nectar was determined by gently pulling a flower or bud from its calyx and firmly pressing its base against a hard surface. A droplet of nectar appeared if is was present. Droplets of nectar were not seen in calyces after corollas were artificially removed. Pollen was detected when anthers that contained it were rolled between my fingers During the observation period, each plant bore up to 30 flowers and flower buds of various sizes Flowers usually opened each day on each study plant. This finding suggests that P. hymenaea has a "steady state phenology" in the terminology of Gentry (1973, 1974a, 1974c, 1976). Flower buds opened in the morning (0600 to 0800), late afternoon (1700 to 1800), and possibly during the night. Flowers did not close after openina and lasted fcr three days. On the first day. the flowers were dark lavender with white corolla tubes: on the second day, light lavender (sometimes splotched with dark lavender) with. white corolla tubes; and on the third day, very light lavender or white. Seventy percent of the anthers of large buds contained pollen at 0600 and 80 percent at 1800. Large buds did not contain pollen at other times of the day, and the buds never contained nectar. Dark flowers are 0 to 24 hours old, and light ones are 25 to 72 hours old. Ninety percent of the dark flowers contained pollen at 0600; 90 percent at 0900; 70 percent at 1200; 80 percent at 1500; and 10 percent at 1800. Seventy percent of the dark flowers contained nectar at 0900, and 20 percent at 1200. They did not contain nectar at other times of the day. Light flowers did not contain pollen, and 40 percent of them contained nectar at 0600. None contained it at other times of the day. Although light-colored flowers did not contain pollen and usually did not bear nectar, they were retained on inflorescences for one to two days rather than being dropped Retention of light-colored flowers on inflorescenses might function in attracting pollinators to plants of P. hymenaea, because plants with both light and dark flowers might be more conspicuous to pollinators than plants with only dark flowers. Of the 150 flowers and large buds examined, 7 percent suffered corclla predation, in that part of a petal, or all petals and sometimes part of the corolla tube were missing. The ovaries of 57 percent of the flowers and large buds were preyed upon by weevil larvae (Curculionidae). All ovules were destroyed in predated ovaries. Leaflet predation also was frequent. If the plant's garlic-like odor inhibits predatien by arthrorods as suoggested by Gentry (1974a), it app-re-tly does not stop all of them. The odor may even attract pollinators. One to 50 mature and immature thrips, Franklinielle insularis Froonklin (Thysanoptera: Thripidae), inhabi,ted 50 percent of the 150 flowers. Thrips were BIOTROPICA 9(2): 133-134 1977 133 This content downloaded from 40.77.167.9 on Sat, 06 Aug 2016 06:29:09 UTC All use subject to http://about.jstor.org/terms not inside buds but commonly in their calyces, indicating that the thrips entered the flowers after they opened. The following ants (Hymenoptera: Formicidae) crawled over P. hymenaea: Campanotus rectangularis Emery, Phedole pugnax D.T., Pseudomyrmex fulvescens Emery, P. near gracilis (Fabr.), P. mexicanus (Roger), and Zacryptocorus minutus (Fabr.). Only Pseudomyrmex species were common, and they presumably crawled into flowers to rob nectar. It is doubtful that any of the ants are effective pollinators of P. hymenaea (R. R. Snelling, pers. comm.). Ants may have been ccllecting nectar from its vegetative