Flora of the Hawaiian Islands
Dicotyledon Literature for Rockia sandwicensis
Wagner et al., 1990, 1999.
   Nyctaginaceae -- The Four-o'clock Family Bibliography
      Rockia sandwicensis
General Information
DistributionIn the Hawaiian Islands, endemic to Kaua`i, O`ahu, Moloka`i, Lana`i, Maui, Hawai`i.

Nyctaginaceae - Rockia sandwicensis















Click here for detailed USGS map by Jonathan Price
HabitatDry to mesic forests, usually on slopes or in gulches
Elevation260-1040 m
Habit
Small trees to 12-15 m tall, openly branched; branchlets rather thick, distal internodes becoming very short, rarely congested to aggregate nodes, youngest growth brown tomentulose, glabrate.
Leaves
Leaves opposite or distally some of them somewhat alternate, thick and chartaceous to usually coriaceous, oblong to occasionally ovate-elliptic or broadly elliptic, 10-28(-31) cm long, 5-10(-16) cm wide, primary lateral nerves 9-12 pairs, conspicuous, forking and anastomosing toward margins, tertiary and higher order venation faint but visible, forming areolae of several orders, glabrate, apex obtuse or rarely bluntly acute or rounded, base abruptly contracted, rounded to subtruncate, the sides often unequal, petioles 2-6 cm long, stout, tomentulose, becoming glabrate.
Flowers
Flowers unisexual, weakly fragrant, short-pedicellate to sessile, in long-pedunculate, globose to hemispherical, axillary cymes (4-)6-10 cm long at anthesis, elongating up to rarely 20 cm long in fruit, densely to moderately brown tomentose, main branching thyrsoid to umbelloid, branched portion of cyme usually globose, branching of cymules more irregular, scale-like bracts thick, prominent at articulations, often appearing calyculate at bases of pedicels or of flowers; staminate flowers densely tomentose, perianth brownish, tube prismatic to cylindrical, occasionally somewhat ampliate upward, 3-5 mm long, lobes oblong, 2-4 mm long, 1-2 mm wide, recurved, tomentose externally, glabrous within, stamens (10-)15-28(-30), exserted, from once to twice the length of perianth tube, anthers orbicular, pistillode usually included but in some specimens exserted to as much as 1/2 the length of the stamens, rudimentary stigma recurved, flattened, somewhat pilose; pistillate flowers with perianth similar to that of staminate flowers, but soon elongating, staminodia usually included, occasionally sterile anthers visible in perianth throat, very rarely exserted so that flowers resemble staminate except that anthers are sterile, though dehiscent, style glabrous, exserted to length of perianth lobes, stigma flattened, lanceolate or paddle-shaped, covered with elongate hair-like branching processes or fimbriate, stigma usually recurved, rarely, even on same plant, shorter, slightly branched and spreading, but abundantly covered with hair-like processes, but in some specimens straight and erect.
Fruit
Anthocarps prismatic, 3-6.5 cm long (erroneously reported in literature to be 37.5 cm long), up to 7.5 mm in diameter at widest part, ca. 1 cm above base, upper 1/3-1/2 usually, but not always, tapering to a slender sterile rostrum, crowned by the erect persistent lobes, the 5 angles smooth but very glutinous.