30 



A MONTANE RAIN-FOREST. 



The terrestrial herbaceous vegetation varies more with the physio- 

 graphic age of the ravine than does the arborescent vegetation, the 

 initial ravines, with steep sides and rocky floor, differing from the 

 sequential ones with more open sides and a deeper soil. The beds of 

 steep and narrow ravines are often covered with coarse stones to so 

 great a depth as to be almost devoid of large herbaceous plants, yet the 

 stones themselves are covered with Monoclea or with mats of Pallet 

 vicinia, Riccardia, or Plagiochila, together with small filmy ferns, such 

 as Trichomanes pyxidiferum, Trichomanes reptans, and Trichomanes 

 hookeri. A few small flowering plants of pronouncedly hygrophilous 

 character also occur in rocky ravines and on the steepest slopes that 

 are deeply shaded, as Peperomia hispidula, Peperomia filiformis, Hydro- 

 cotyle pusilla, Pilea brittonice, and Gesnera mimuloides. 



The beds of somewhat wider ravines provide soil of sufficient depth 

 to support a dense growth of coarse ferns (see plate 2) . The commonest 

 and most wide spread species of ferns in such situations are Diplazium 

 celtidifolium, Diplazium costale, Asplenium alatum, Dennstcedtia sp., 

 Diplazium altissimum, Diplazium brunneoviride, Dancea jamaicensis, 

 Asplenium rhizophorum, and Marattia alata, and with them grow less 

 frequently or more sporadically a large number of other species. The 

 wider and more shallow ravines have a less number of ferns in their 

 herbaceous vegetation and a greater number of flowering plants, not- 

 ably Pilea nigrescens, Peperomia turfosa, Peperomia obtusifolia, and 

 Pilea parietaria, together with the less frequent Physurus hirtellus, 

 Calanthe mexicana, Prescottia stachyodes, and Liparis elata. 



The trunks and limbs of the massive trees of the Windward Ravines 

 bear a profuse epiphytic vegetation, which will be treated under a later 

 heading. A small number of species of lianes are present, which are 

 far from playing the role of the plants of this habit in the lowland 

 forests. Marcgravia brownei is by far the largest and most striking of 

 the climbers, growing into the canopy of the forest, filling the crowns 

 of the largest trees, and hanging in graceful festoons from their lower 

 limbs. Its juvenile shoots are commonly seen growing closely appressed 

 to smooth naked trunks, their small deltoid leaves forming a striking 

 contrast to the long pinnate leaves of the adult shoots. Anthurium 

 scandens is the only climbing aroid; its small simple leaves give it a 

 far less important place in the physiognomy of the vegetation than is 

 held by the species of Anthurium and Philodendron of the lowlands. 

 Other frequent lianes are Smilax celastroides, Blakea trinervis, Metas- 

 telma fawcettii, Metastelma atrorubens, Bidens shrevei, and Begonia scan- 

 dens. Among the ferns Blechnum attenuatum and Polypodium loriceum 

 are common in ravines and slopes alike, but seldom clinib far above 

 mid-height in the forest. The climbing filmy-ferns, Trichomanes radi- 

 cans and Trichomanes scandens, are confined to deep shade in the 

 narrowest ravines and seldom reach over 6 feet from the ground. 



