[S. laysanensis St. John; S. microcarpus H. Mann; S. m. subsp. kanepuuensis St. John; S. m. subsp. lanaiensis St. John; S. m. subsp. /. var. kamoaensis St. John; S. m. subsp. /. var. kealiaensis St. John; S. m. subsp. /. var. koeleensis St. John; S. m. subsp. /. var. oniniensis St. John; S. m. subsp. /. var. trilobata St. John; S. m. subsp. laysanensis (St. John) St. John; S. m. subsp. /. var. ewaensis St. John; S. m. subsp. /. var. haleakalaensis St. John; S. m. subsp. I. var. kauensis St. John; S. m. subsp. /. var. koloaensis St. John; S. m. subsp. /. var. meeboldii St. John; S. m. subsp. /. var. obovoideis St. John; S. m. subsp. microcarpus var. forbesii St. John; S. m. subsp. m. var. kaiaupapaensis St. John; S. m. subsp. m. var. kilaueaensis St. John; S. m. subsp. m. var. paneensis St. John; S. m. subsp. m. var. pohakeaensis St. John; S. m. subsp. m. var. woolfordii St. John; S. m. subsp. puberulus St. John; S. niger St. John; S. nihoaensis St. John; S. remyanus Cogn.] (end) Kupala Climbing vines, perhaps with perennial rootstock; stems slender, up to several m long, ca. 1 mm in diameter, glabrous. Leaves broadly ovate-cordate or reniform with a broad basal sinus, 7-26 cm long, 7- 28 cm wide, usually shallowly 5-7-lobed or angled, rarely deeply 5-7-lobed, the lobes usually broadly triangular, rarely narrowly obovate and lobulate, denticulate, usually obtuse and mucronate, the central lobe abruptly acuminate, the slender apex often breaking early, glabrous or upper surface sparsely scabrid, lower surface scabrid with short white hairs, petioles 1.5-3 cm long, tendrils 2-branched. Staminate flowers in pubescent or puberulent panicles 3-12 cm long, peduncles 2-9 cm long, pedicels 2-3 mm long, corolla greenish yellow, 5-lobed, 3-5 mm in diameter, anthers coherent, rarely spreading; pistillate flowers (5—)10— 50 per head, sessile on peduncles 0.4-2(-4) cm long, hypanthium ovoid, attenuate, ca. 3 mm long, glabrous or puberulent, especially toward apex, corolla 3-5-lobed, stigma shortly 3-lobed, the lobes recurved. Fruit brown or black, ovoid, attenuate, 3-8 mm long (incl. beak), compressed or angled toward base, glabrous or puberulent, abruptly contracted into a short beak. [2n = 24*.] Widespread in herb or shrubland coastal communities, dry forest, and alien vegetation such as Leucaena or Prosopis shrubland, on coral sand or clay loam, 0- 900 m, primarily on the lower leeward slopes of all of the main islands; also on the Northwestern Hawaiian Islands where collected from Laysan and Nihoa.—Plate 77. Sicyos pachycarpus is an extremely variable species, particularly in pistillate inflo-rescences, peduncle length, number of flowers per head, and hypanthium shape and vestiture. Some populations are difficult to place. On Moloka‘i, they appear to grade into S. erostratus. On Maui, they are very similar to S. hillebrandii. Additional collections and field studies are required. Some collections from Laysan with stout petioles may represent hybrids with S. maximowiczii. This species has long been referred to as Sicyos microcarpus. The type material of S. pachycarpus (Lay & Collie s.n., K) is a mixed collection, one element of which is the present species. Hooker and Arnott’s description (1832) better fits this species and will be lectotypified to stabilize this interpretation. The other element of the Lay and Collie collection is S. waimana- loensis