Alexandre Falconer), on Tridacna and Pisonia, most probably 

 in coastal Tournefortia scrub. 



RUBIACEAE 



* Morinda citrifolia L. (Fig. 25; PI. 48) 



Formerly Known Distribution : Reported 1840, collected 

 1884. L-32 14. 32 17 and 3282: 3232; 3254 on South, Nake, and 

 Long, respectively. 



Present Distribution : K-90-4, 18 from South Island, 

 lagoon edge, and Ana-Ana. respectively. Range extension on 

 Caroline from 3 to 30 motus (Table 3). 



Abundance : Coverage from 2% to 50%. Basically an 

 inland species, widespread and predictable in scrub and forest 

 understory. Rarely a component of the canopy, except on 

 Raurau. where Morinda grows 12 m tall in a 13 m Pisonia 

 forest. Essentially associated with established Tournefortia 

 woodlands on motus greater than one hectare in size. Quite 

 common on South Island despite major disturbance, occurring 

 within beach strand, Cocos plantations, and Cocos-Ipomoea 

 interior. Best locations (40-60% coverage): Nake. Tr. 3; 

 Tridacna, both transects; Long, Tr. 8; Raurau and Ana-Ana. 



Ecology : Appears early in plant succession: inToumefortia 

 scrub as an early pioneer (Stage I), then from Stages II to IV, 

 progressively becoming more common and robust. Not in pure 

 Pisonia forest (Stage V). Much less common in Pandanus 

 stands. Although it thrives best in light to heavy shade, 

 preferably growing in moist "soil," one leathery seedling (7 cm 

 high) had gained a foothold in exposed rubbly Heliotropium 

 flats on Fishball Islet. 



Biogeographical Note : Generally considered a naturalized 

 aboriginal introduction on most Pacific islands. Morinda could 

 be native to Caroline, as theorized for the northern Line Islands 

 (Wester, 1985). Although possibly introduced by early 

 Tuamotuan settlers, its present distribution strongly suggests 

 that it is indigenous. Throughout the atoll Morinda occurs in 

 the greatest densities on motus with no anthropogenic forests 

 or in areas distant from historical settlements (Fig. 26). On 

 Nake, Morinda occurs frequentl — in places abundantly — within 

 the interior Pisonia forests, yet its coverage is only 5-10% in 

 mixed Pandanus— Cocos forests in the southern sector. It also 

 appears to be part of natural biological succession (Table 6). 

 Further support for this theory comes from nearby Flint. 

 Though there is no direct archaeological evidence that Flint 

 was settled in prehistoric times (Garnett, 1983), our 1990 

 surveys found Morinda in all habitats (mixed woodland, native 

 coastal scrub. Cocos plantations, and abandoned settlement). 



Originating in Polynesia, Morinda has been widely 

 dispersed by man but has apparently also spread, unaided by 

 man. "widely by sea in the Malayan and Polynesian Islands" 

 (Ridley, 1930). Its air-filled, buoyant pyrenes can float for at 

 least 53 days and "its seeds are almost certainly disseminated 

 by birds and bats" (Guppy, 1906). It could also be disseminated 

 by Coenobita crabs and rats within and between motus, as has 

 been found elsewhere by Ridley. 



Phenology : Flowers and fruits year round. 



Substrata : Coral rubble, gravel, sand, and humus. Rarely 

 found in coarse clinker. On larger motus. prefers moist soils 

 under tall forests. 



GOODENIACEAE 



c * Scaevola sericea var. sericea Vahl (Fig. 1 1 ) 



Scaevola taccada var. sericea (Vahl) St. John 



Never previously collected. K-88-2, Windward Islet, 

 central-windward side, elevation 0.3 m. 



Distribution and Abundance : One wind- and salt-sheared 

 "hedge," found by K. Teeb'aki on Windward Islet, was growing 

 on a coarse rubble beach. "The saltbush..., being recorded for 

 the first time too from the island. ..covered approximately 3% 

 of the islet's land area [this probably can be translated as "3% 

 of the area covered at that location on the transect." as we 

 understood from Mr. Teeb'aki's description that it was quite 

 small], occupying the mid-windward side. The patch grew 

 very low — only up to 2' high with its foliage forming an 

 extended raised mat canopy all along the area it occupied" 

 (Teeb'aki, 1988). We have been unable to return to this spot to 

 observe and photograph it directly. 



Because Scaevola is hardy, halophytic, and widespread in 

 the Pacific, it is surprising that it is so rare on Caroline. 

 However, none occur on Vostok, and only one clump is known 

 from Flint (Clapp & Sibley, 1971b; Garnett, 1983). Fosberg 

 (1953) noted that Scaevola seeds are transported by bristle- 

 thighed curlews (Numenius taitensis) in the Marshall Islands: 

 curlews are common on Caroline ( Subchapter 1 .2, this volume) 

 and could have brought seeds from elsewhere. 



Substrata : Coarse rubble, windward beach. 



° * Scaevola sericea var. tuamotensis (Si. John)Fosb. (Fig. 1 1 ) 

 Scaevola taccada tuamotensis St. John 



Never previously collected. K-90-168 (collected by 

 Alexandre Falconer), northeast peninsula. South Island, in 

 coral rubble. 



Present Distribution : One individual, of unknown size. 

 with Suriana and Heliotropium, northeast peninsula, South 

 Island, facing the inner side of the "blind passage." 



Floristics and Ecology of the Motus 



Size of the Flora : Atoll floras characteristically lack 

 diversity. Numbers of species range from 3 to around 150 in the 

 Pacific and 284 in the Indian Ocean. The flora of the Southern 

 Line Islands is particularly impoverished because of /. their 

 easterly location ( far from the major source areas of Australasia); 



2. low profiles (most only rise a few meters above sea level); 



3. lack of topographic diversity (most have a very limited range 

 of habitats); 4. low to medium rainfall (approximately 

 1,500 mm p. a.); and 5. edaphic factors such as salinity, highly 

 calcareous soils, et cetera. Long-distance dispersal and hardiness 

 are important factors in establishing a flora, especially since the 

 closest high island, Tahiti, is 830 km away, and the ultimate 

 source of its flora, the Malayan-Melanesian region, is over 

 8.000 km away. South America, the closest continent, is 



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