SELENIPEDIUM 



rather stiff upright, about 1 ft. long: scape 12-24 in. 

 high, about 4-fld.: dorsal sepals 5-6 in. long, lanceolate, 

 pale yellow, verging on creamy white and veined with 

 greenish, lower sepal similar; petals pendent, twisted, 

 often attaining a length of nearly a yard, yellowish, 

 shaded with brown on the outside and becoming brown- 

 ish crimson toward the tips. Peru. F.S. 6:566 R H 

 1857, p. 318; 1883, p. 351; 1885, p. 472. G.C. II. 3:211; 

 26:269. Gn. 3, p. 313; 26, p. 72; 32, p. 301; 46, p. 85 AF 

 3:132; 6:859. Gng. 5:265. G.M. 31:557; 33:795; 35:489 



SKLF-STKKILITY 



1653 



23 J9. Selenipedium Dominianum (Xl-5). 



Onp of the largest of the Selenipediums and remark- 

 able 011 account of the extremely long petals. Peloric 

 forms with the third sepal (labellum) resembling the 

 other two have passed under the name of Uropedium 

 Lindeni, Lindl. 



Var. rdseum, Hort. (S. caudatum, var. Warscewiczii, 

 Godfrey.). Sepals yellow, with orange veins ; petals 

 deep purple ; labellum deep yellow in front, green be- 

 hind. I.H. 33:596. Var. Wallisii, Hort. (S. Wdllisii, 

 Reichb. f . Cypripedium Wdllisii, Hort.). Lvs. paler 

 green: fls. pale, and in everyway mere delicate than 

 the type. Gn. 49, p. 140. Numerous other varieties of 

 this species are distinguished in cultivation. The fol- 

 lowing names occur in trade lists : aiireum, Luxembur- 

 g6nse, rubrum, supSrbum, Seegerii, splendens, nigres- 

 cens. 



15. grande, Reichb. f. (Cypripedium grdnde, Reichb. 

 f. ). A garden hybrid between S. BoKzlii and S. cauda- 

 titm, resembling the former in habit and flowers but 

 much more vigorous, with darker fls. : Ivs. dark green, 

 over 2 ft. long: scape over 3 ft. high, with several large. 



shining Ms.; >.-|,;ils long, oblong- lanceolate, yellowish 

 White, veined with green; petals lonir. pendent, yellow- 

 ish green above, becoming rose pink; lulu-limn large, 

 greenish yellow in front, whitish behind: -i-le lol>e^ 

 white, spotted with eriawoa. <;..M. :!_':*:. ,\.r. ii:i.u'.i. 

 Var. atratum. A hybrid between >'. /"in/ifnlunn . / 

 lit* and S. ritu<l<itun< n>.i,-unt. U.C. 111. 1 



16. Dominianum, Hort. | ri//<,-//,/, /,/;, l>.:,in,n 

 Kei.-hb. f. ). Fi^'. L':;O'.I. Lvs. nunu-r<ni>. about I ft. \im, 

 acuminate: fls. yellowish irr.-en. with copper I.P.W n 

 shades and markings ; labellum deep reddish brown, 

 reticulated in front and yellowish green behind. A hy- 

 l>rid between &'. Pearcei and N. caudal nm. It i- inter 

 mediate between the parents, but differs from S. cauda- 

 tum by its acute bracts and narrower Ivs., from S. 

 Pearcei by the transverse staminode and hairy ovary. 

 Gn. 3, p. 491. F. 1874, p. 57.-The following varieties are 

 also distinguished in cultivation: elegans, nibescens, 

 super bum. 



17. Boissierianum, Reichb. f. (Cypripedium reticula- 

 tum, Reichb. f.). Plant of vigorous habit: Ivs. about 3 

 ft. long, acuminate: scape few-fld. or sometimes pani- 

 culate, 3-7-fld. : fls. of peculiar light green tints, with a 

 few sepia brown and green blotches on the whitish in- 

 flexed part of the lip and with some brown spots on the 

 margins of the sepals: ovary dark brown, with green 

 apex and ribs; upper sepals ligulate-lanceolate, very 

 crisp; lower sepals oblong, about equal to the labellum, 

 crisp; petals spreading, long-linear, twisted and very 

 crisp on the margins. Peru. G.C. III. 1:143; 21:54, 55. 

 G.F. 4:605. 



18. Klotzschianum, Reichb. f. (Cypripedium Schom- 

 burgkianum, Klotzsch and Reichb. f. ). Lvs. linear, 6- 

 12 in. long, scarcely % in. wide, rigid, keeled: scape 

 longer than the Ivs., hirsute, purple, 2-3-fld.; dorsal 

 sepal ovate-lanceolate, pale rose-colored, with reddish 

 brown veins, the lower ovate, boat-shaped, colored like 

 the upper one; petals 3% in. long, linear, twisted, col- 

 ored like the sepal; labellum greenish yellow, the in- 

 flexed side -lobes whitish, spotted. British Guiana. 

 B.M. 7178. G.C. III. 15:625. 



19. caricinum, Reichb. f. (Cypripediut/i Pearcei, 

 Hort. Cypripedium caricinum. Lindl. & I'axt. i Lvs. 1 

 ft. long, springing in sedge-like tufts from the long 

 creeping rhizome: scape longer than the Ivs., 3-6-fld.: 

 fls. mostly pale greenish, with the segments bordered 

 with white and having purple tips; sepals broadly ovate, 

 waved, as long as the lip; petals more than twice as 

 long, pendent, narrow and much twisted ; labellum ob- 

 long, the upper margins flat ; staminodium provided 

 with 2 hairy processes. Peru. B.M. 5466. F.S. 16:1648. 



HEINRICH HASSELBRING. 

 SELF-HEAL. See Brunelln. 



SELF-STERILITY OF FRUITS. Self-sterility may 

 be roughly defined as the inability of a given plant to 

 produce fertile seeds when pollinated with its own pol- 

 len. With the rapid strides in plant-breeding, propaga- 

 tion and cultivation, self-sterility and sterility have be- 

 come important subjects in determining the value and 

 adaptability of new varieties to the various needs and 

 purposes of the planter. 



The study of self-sterility in more recent years has 

 been confined mostly to fruit trees and small fruits, 

 and has been conducted by a number of experiment 

 station workers. The list of self-sterile and unisexual 

 varieties is now fairly large for apples, pears, plums, 

 grapes and strawberries. In the case of peaches, apri- 

 cots, cherries, nectarines and prunes little has been done 

 to determine the number of self-sterile and partially self- 

 sterile varieties. The causes which tend to produce 

 self-sterility in cultivated plants may be briefly sum- 

 marized as follows: 



(1) Change of environment due to domestication pro- 

 duces change in the reproductive organs of the plants. 

 It may result (a) in the suppression in whole or in part 

 of either stamens or pistils; (6) in the infertility or 

 impotency of the pollen upon its own pistils; (c) in 

 changing the time of ripening of the pollen and of the 

 receptivity of the stigma. 



(2) Asexual propagation tends to reduce the impor- 

 tance of seed production, and to transmit and fur- 



