72 



HORTICULTURE, 



July 20, 1907 



TWO ANDEAN ORCHIDS. 



For teauty, variety, aud natural in- 

 terest combined the orcliids surpass 

 every other family of flowering plants. 

 No other group approaches them in 

 brilliant, singular and various color- 

 ing, in exquisite, graceful or sculp- 

 tural, or fantastic form of flower, in 

 peculiarly rare and delicate beauty of 

 our native kinds — as Arethusa, Calyp- 

 so, Calopogon — or in the remarkable 

 relations which the flower has estab- 

 lished with the insect world. Only 

 two other great natural families equal 

 this in number of species, for the or- 

 chids of the globe embrace some 

 seven or eight thousand kinds already 

 described and named by botanists, and 

 are thus more numerous than all the 

 species of flowering plants known to 

 Linnaeus. They inhabit all quarters 

 of the globe from Alaska, Iceland and 

 Siberia to the equator and beyond to 

 antipodal cold; but they are most at 

 home in the hot and damp tropical 

 belt, especially in the rain forests o£ 

 tropical mountain ranges. Here they 

 diversify themselves endlessly and dis- 

 play to perfection that remarkable 

 adaptability which to some observers 

 seems akin to our own rationality. 



Charms of the Small Flowered 

 Orchids. 



The popularity of orchids in fine 

 greenhouse collections is due to floral 

 beauty. Few pursuits can afford the 

 lover of rare and beautiful plants 

 greater delight than the collection and 

 cultivation of vandas, dendrobiums, 

 calanthes, odontoglossums, etc. Here 

 and there, however, we find one who 

 extends his search beyond the large- 

 flowered forms to those which are 

 smaller and perhaps rarer, and exert 

 a different charm. To such a plant 

 lover the unexpected and curious is 

 apt to appeal strongly, especially if 

 joined with winning floral qualities. 

 Consequently, some large collections 

 include not only showy species, like 

 the cattleyas, but those of more lowly 

 station and of less fame with the 

 florist, known and admired chiefly by 

 true orchid amateurs, — among which 

 are the Masdevallias. The plants are 

 small, some of them tiny, and tufted. 

 They are native of South America and 

 are hard to grow well in our climate, 

 since they naturally inhabit the for- 

 ests and rocks of the Andes, where 

 the temperature in the open sun is 

 very high, while shade leads to rapid 

 cooling and the night temperature 

 may be comparatively low, and where 

 the mountain winds give good aera- 

 tion at all times — conditions quite the 

 reverse of greenhouse climate during 

 our American summer. The flowers 

 are in a few species brilliant, in many 

 delicately beautiful, and in all very 

 curiously formed. The number of 

 species is large. The activity of 

 the flower in two of the species — the 

 subject of the present sketch — is most 

 remarkable. 



Where Masdevallias Thrive. 



Masdevallia muscosa and M. 

 Xipheres have recently bloomed in the 

 greenhouse at North Easton and I 

 have had an opportunity to watch 

 their behavior. In their native Coltim- 

 blan forests they grow upon limbs of 

 trees, on rocks, and sometimes among 

 the mosses of the forest floor. Fre- 

 quent rains keep them well-watered 

 in the wet season, even when they are 



U^^^ 



seated upon naked treetrunks or bar- 

 ren rocks, while at all seasons of the 

 year the nightly dew-falls are copious. 

 The roots are spongy and rapidly soak 

 up water-supplies when available, 

 while the leaves are rather thick and 

 act as reservoirs. There is thus no 

 occasion for employing that remark- 

 able power popularly ascribed to tree- 

 dwelling orchids, of condensing and 

 absorbing water vapor from the air — • 

 a power which, in fact, they do not 

 possess. In nature only the rains and 

 dews make it possible for "air plants" 

 to thrive. 



The Mossy Masdevallia (Masdeval- 

 lia muscosa) is so named I suppose 

 for the shaggy and moss-like flower- 

 stalks. The flowers are golden, their 

 stalks light green, the foliage is dark 

 green, and the little plants must be 

 particularly pretty as they stand in 

 the sun in nooks of the lava-walls of 

 mountain ravines, 6000 to 8000 feet 

 up on the slopes of the Andes. The 

 three sepals are joined at the base 

 into a triangular chalice, which in- 

 cludes the two narrow petals and the 

 column. The lip is pendant from a 

 point within the lower margin. It has 

 a thin high crest running lengthwise, 

 and an expanded extremity beset with 

 tufts of maroon hairs. It now, when 

 the flower is open, the crest of the lip 

 is touched ever so slightly, even 



stroked with a hair, it begins instantly 

 to close up, first slowly, but after two 

 or three seconds flying up with a sud- 

 den snap. The shut lip exactly closes 

 the opening of the triangular cup, as 

 shown in the upper flower of the 

 drawing, except at the top, where the 

 ends of the petals and the column 

 protrude somewhat, and moreover 

 leave a small opening. After a period 

 of twenty minutes more or less, if the 

 lip is not further excited it begins to 

 open and slowly falls to its former 

 position, when it is ready to be sprung 

 again. I set the lip of one flower off 

 repeatedly during a day or two, and it 

 lost none of its sensitiveness; in fact 

 it recovered rather more quickly at 

 the end of this time. 



A variety of stimuli besides touch 

 were found to cause the movement. 

 Oil taking the plant out of doors, into 

 air of about 46 Fah., the lip promptly 

 closed. A hot needle brought near 

 the cushion had the same effect. Most 

 curious of all, about an hour after 

 nightfall the flower closed (although 

 darkening during the day was ineffec- 

 tive), and remained so until an hour 

 or more before light next morning, 

 when it opened of its own accord. 



Fertilization by Means of Insects. 

 Only the ridge or crest of the lip is 

 sensitive and must be touched, and 



