66 USEFUL PLANTS OF GUAM. 



example belonging to the Oxalidaceae. This is Averrhoa carmribola, 

 the " bilimbines" of the natives, a tree which yields a pellucid oval- 

 shaped, five-angled fruit. (PL XXXVII.) Its foliage is not only 

 sensitive to light and darkness, sunshine and shade, but also to sudden 

 mechanical shocks, the leaves bending and their leaflets folding very 

 much as in the case of the sensitive plant (Mimosa pudica). Besides 

 the above-mentioned plants are several species of Cassia, Caesalpinia, 

 Erythrina indica and other Leguminosae; and, among the Euphor- 

 biaceae, two or three species of Phyllanthus and Euphorbia. 



PLANTS WHICH SELDOM BLOOM. 



Many plants grow spontaneously on the island which in many other 

 parts of the world are seen only in a state of cultivation. The plant 

 which produces the celebrated "rhea" fiber, Boehmeria tenacissima, 

 which in cultivation is herbaceous and seldom flowers, grows spontane- 

 ously in Guam in the form of a shrub or small tree, called in the island 

 vernacular "amahayan." Species of Colocasia and Alocasia, which 

 seldom bloom in cultivation, and which are classified according to their 

 inflorescence, here appear to grow in a state of nature. Their soft, 

 fleshy spathes should be collected and preserved in alcohol or formalin 

 for comparison with species and varieties from other localities. Bam- 

 boos also are among the plants which seldom flower. The species 

 growing in Guam have not yet been identified with certainty owing 

 to the lack of good specimens of inflorescence. In cultivation all the 

 plants "here mentioned are propagated asexually, and are divided into 

 a number of varieties. 



PLANTS WITH EXTEAFLOEAL NECTAEIES. 



There are perhaps few localities which offer better facilities for the 

 observation of extrafloral nectarie's. Here within a small area, grow- 

 ing not in conservatories, but in a state of nature, may be observed a 

 remarkably large number of plants having glands on the midribs, 

 veins, petioles, or rachis of their leaves, or on the peduncles, pedicels, 

 or sepals of their flowers. Among them are species of Cassia, Eryth- 

 rina, and Acacia, with stalked disk or cup-like glands, and, belonging 

 to the Euphorbiaceae, the candle-nut (Aleurites) and the well-known 

 castor bean with well-marked nectaries at the junction of the blade 

 and the petiole of the leaf. 



Ricinus communis is especially well provided with these nectar 

 glands. They occur on the nodes of the stem, along the petioles of 

 the leaves, and the serrations of the leaf blades (PI. IX, fig. 2), as well 

 as at the base of the blade where it is joined by the petiole. At this 

 point there are usually two nectaries, though there may be but one, 

 or there may be three or four when the leaf lias a greater number of 

 lobes than usual. Many of the Euphorbiaceae are provided with extra- 



