July S. 191G 



HORTICULTURE 



41 



The Androsaces 



Aniou.u- the nmiv dillit-ult of llu' rock-pliints. (jr alpiiic:^ 

 aiv these little iiiemboi-s of the I'liiuula family, hailing 

 from the highest parts of the Al|i.<. aiul living there in 

 such intense cold and under sueh exti'enie conditions 

 that any other plant life, except that equally well pi-o- 

 vided. would perish. 



Typical endemic species of I hi- harsh climate, they 

 represent a class of plants tluit may well be called 

 "cushion plants." forming, as they do, a moss-like, com- 

 pact growth in adaptation to the combined cold and di\- 

 ness of their habitat. They are the most alpine of alpine 

 plants. In a number of cases of alpines we find 

 representatives in the lowci- hill |)astures or sunny 

 meadows, but not >o with the Androsaces. C4entians 

 and Primulas will be found in the lower land, but imt 

 the Androsaces. As a natural result they arc the dwai 1- 

 est of the class, some of the smallest Primulas l)eing 

 giants in size compared with them. 



The Androsaces resemble the Primula in flower, agree- 

 ing in most characteristics, but having the tube of thr 

 corolla narrower at the mouth. On account of the short 

 summer in their habitat their flowers open as soon as 

 the snow is melted. They can l)e grown in a properly 

 formed rock garden in pure air. with good drainage, 

 but are sure to die quickly in a smoky atmosphere, and 

 stagnant water is fatal. Their small, downy evergi-cen 

 leaves (simie have smooth leaves) will retain much more 

 dust thai) many of the other smoother and larger-leaved 

 pvergreen alpines. The Androsaces will thrive in small 

 fissures between firm rocks or stones, firmly packed in a 

 sandy peat or a very sandy or gritty loam, not less than 

 fifteen inches deep. They should be placed so that no 

 moisture will get at them in winter and so that in suuj.- 

 mer they may enjoy a cool soil in a moist atmosphere 

 with plenty of sun. It is all the better if a few pieces 

 of sandstone can be strewn over the surface of the lied 

 so that once the ground beneath is well moistened, they 

 \\\\\ not suffer from any ordinary drought. They are 

 not deeprooted plants, provided they can get a supply of 

 water near the surface, and always prefer to send their 

 roots along the face of .some stone at a small dejith. 

 rather than to sink vertically to any considerable dis- 

 tance. Shade with them is entirely out of the question. 



If such a condition as that named above cannot be 

 given, some chances of success may be gotten from a 

 level bed of sandy peat, provided it is well drained and 

 the plants protected from moisture in winter bv placing 

 a piece of glass over them. Here great care must lie 

 taken to keep out the stronger growing plants, which 

 such a soil and condition favors, for they will soon shade 

 and kill the smaller plants. 



Tlie following is a short description .of smne cd' the 

 best known varieties. 



A. carnea: One of tile prettiest and most distinct. Very 

 early. Known by its small pointed leaves, not gathered in 

 rosettes but regularly clothing the somewhat elongated 

 stem like a small twig of Juniper. Flowers a lively pink 

 or rose with yellow eye. Easily propagated from seed sown 

 in pans of sandy soil as soon as gathered; also by division. 



A. carnea var. eximea: Larger than the last, hardier and 

 more roluist. Flowers exactly like the above exiopt one 

 inch larger and of more substance. Grows very rapidly 

 in tufts three inches high with leaves about one inch long 

 and one-eighth inch wide at the base. A limestone soil is 

 fatal. Increased by division. 



A. Brigantica: In every way like the last named variety 

 except flowers white. The same position and soil suits it. 



A. Chamaejasme (Rock .lasmine): This species does not 

 form the close cushion-like growths like some of the others 

 hut makes larger rosettes of fringed leaves. The flowers 

 are borne on stout stems, rarely more than an inch in 

 height but varying from that to five inches in some cases, 



according to the vigor of the plants and their position. 

 Flowers freely. This plant is one of the most wortliy of 

 culture of all alpines and one of the easiest to grow on 

 open rock work in a deep and well drained rich light loam 

 in a sunny position, the surface of the soil being almost 

 completely covered witli small pieces of sandstone to pre- 

 vent evaporation and also to preserve the plant from in- 

 jury. It should get plenty of water diiring the summer 

 mouths and be exposed to the full sun. It dislikes lime 

 and succeeds best in ri\er sand and peat. 



A. ciliata (Fringed .Vudrosace): Practically identical 

 with the above but with fewer flower-stems and twice as 

 long as the leaves. This iilant is, by some, considered a 

 variety of the above. 



A. cylindrica: This is another variety with stems rising 

 to one-half inch in height, with persistent leaves which 

 form columns on the stems. Flowers pure white in spring. 

 Should be treated like A. pubescens. 



A. Helvetica (Swiss .\ndrosace): This species forms 

 dense cushions about one-half inch in height with small 

 fringed leaves tightly packed in small rosettes. Each 

 rosette rests on lue top of a little column of old and dead, 

 but hidden, and half-dried persistent leaves. Flowers 

 white with yellowish eye. one from each rosette, and about 

 twice as large as the rosette from which it rises. This 

 plant requires considerable care in cultivation, perfect ex- 

 posure to the sun well-drained, but never dry position. 



A. imbricata (syn. A. argentea): Differs from the others 

 in having rosettes of a silvery color. Its pretty white 

 flowers are without stalks and rest so thickly on the rosettes 

 as sometimes to overlap each other. Flowers in summer. 



A. pubescens: Has a rather large so'itary white flower 

 with pure vellow eye rising just above the closely packed 

 leaves, the surface of which is covered with stalked and 

 star-like hairs. The iinopened buds look like small pearls 

 set in a tiny five-cleft cup and are on stems barely rising 

 above the dense cushion formed by the plant. It flowers 

 in July and August in its natural home, out with us will 

 blossom in spring or early summer. 



A sarmentosa: This is a dwarf tufted species from the 

 Himalavas, foinid at elevations of 11,000 to 12,000 feet. 

 Flowers borne in trusses of from ten to twenty blossoms 

 on an erect Primula-li'e scape and at first sight resembling 

 the inflorescence of a bright pink, white-eyed Verbena. It 

 is easily propagated from runners which plentifully over- 

 hang tlie side of a pot. This species is difficult to keep 

 over winter unless protected by a pane of glass. Fine 

 sandstone should he put under the rosettes and all over 

 the stirface of the soil to keep all parts except the root 

 from contact with the soil. A dry calcareous soil is best. 



These and many others may be found to be- \ahuible 

 additions to our rock gardens. In a hot rock garden it 

 will be best to give these plants a northwest exposure. 



All delicate alpines need to be dressed witli leafmold 

 when they start into growth in the spring, and many 

 will shrivel up and die for want of it in the- dry winds 

 of early spring. . , 



It is interesting to note that in the region from whu-.i 

 the Androsaces come in the Alps — namely, the regnui 

 just below the snow line and above the tree line, that 

 there are to be found 1020 different species of whicli 

 some 700 are strictly native to this zone ; the others hav- 

 ing representatives in the hill pastures and nu>adows 

 below the tree line. It is noteworthy that in this zone 

 there is a marked predominance of species that affect 

 moist localities wliich are also found in the north. Some 

 species have been traced back to the Stejipes of Central 

 .\sia from whence they followed the glaciers north, and 

 were,' in the second glacial period, forced south again, 

 landing eventually on the highest summits of the Alps, 

 where, finding conditions suitable to their welfare they 

 have staid ever since. Tliese jonrneyings of plants, while 

 they consume but few words, occupied thousands of 

 years, and it is interesting to read of the wanderings of 

 many species now found in different quarters of the 



-J^C/caJ % 



globe. 



Jaiiiaicn Plain, Mass. 



