1282 



FRITILLARIA 



FROST 



slender, 12-18 in. high: Ivs. 3-7, in 2 or 3 whorls 

 at middle of st., narrow-linear: fls. scarlet, sUghtly 

 mottled within with yellow. Calif. — Said to be very 

 Uke F. recurva, but lower and less leafy and the fls. of 

 different color; it has a smaller bulb and takes more 

 readily to cult. 



26. ImperiaUs, Linn. (Imperialis coronata, Dum. 

 Cours.). Cro\\'N Imperial. Fig. 1583. Height 2-3 ft.: 

 Ivs. numerous, crowded, ascending, J9-I in. wide, high- 

 est often in whorls of 8-10: fls. end of March. B.M. 194 

 and 1215. Gn. 46, p. 101; 52, p. 243. A.G. 13:488. 

 R.B. 20:196. — There are single and double forms in 

 yellow and red, and kinds with fohage striped white, 

 and with gold. There are varieties Aurora, Maximus, 

 and William Rex, red; Sulphureus, sulfur-yeUow ; and 

 Crown upon Crown, Couronne Orange, Red Slagz- 

 waard and others. Var. longipetala, Hort. Gn. 

 56:358, with long segms. Var. chitralensis, Hort., has 

 rich yellow fls.: said to be a common form in Chitral 

 (British India). G.C. III. 47: 171. G.M. 54:682. F. 

 Raddeana Regel, from Turkestan, is somewhat dwarf er, 

 blooms earlier, has floral Ivs. recurved-spreading, fls. 

 straw-colored or greenish yellow and shorter than the 

 pedicels. 



27. recurva, Benth. Height 6-24 in.: st. 2-8-fld., 

 purple, mottled green: Ivs. 6-12, lower ones in whorls of 

 3—4, linear, ascending: fls. narrow, bell-shaped. Calif., 

 Ore. B.M. 6264. Gn. 18:458; 59, p. 415; 61, p. 336. 

 — This has stamens only a little shorter than the 

 perianth, while in the next 3 species they are only 

 half the length of the perianth. Distinct by the color 

 of the fls., which are bright red outside without a 

 trace of purple, and brilliant yellow inside, spotted 

 with red. 



28. liliacea, Lindl. White Fritillary. Height 

 3-12 in.: st. 1-6-fld.: Ivs. on st. few, hnear-oblong or 

 linear, those of the radical tuft narrowly or broadly 

 oblong: fls. between funnel- and bell-shaped, whitish, 

 veined green, not checkered; gland at base of segras. 

 greenish and purple-dotted. Calif, in Coast Range 

 from San Francisco south. Gt. 1871:715. 



29. biflora, Lindl. Black Lily. Chocolate Lily. 

 Height 6-18 in., stout: st. 1-3-fld.: Ivs. 2-6, most of 

 thera near the base, scattered or whorled, oblong: 

 perianth greenish or dark purple or Kned with purple; 

 scgms. elliptic-obovate, with a greenish longitudinal 

 band. S. Calif. — Fls. often described as dark chocolate- 

 brown to nearly black. 



30. camtschatcensis, Ker-Gawl. Mostly wTitten 

 kamtschatcensis and variously misspelled. (Llliuni 

 camtschatcense, Linn.). Black Lily. Height 6-18 in.: 

 St. 1-3-fld.: Ivs. 10-15, lanceolate, the lower ones 

 whorled: fls. livid wine-purple, not checkered, lH in. 

 or less long. Siberia, Alaska. Gt. 5:290. Gn. 25:232; 

 52, p. 242. F.S. 12:1232. G. 14:362. 



F. agrestis, Greene. Bulbs very deep-seated: ste. 1-1 } 2 ft.: 

 Iv3. S-12. oblong-lanceolate to linear-lanceolate: fls. 3-S, on abruptly 

 recurved pedicels, yellowish green, with prominent midnerve on 

 each segm. Calif. — Said by Purdy to occur in 2 forms, one a dainty 

 plant a few inches high with fls. ha\dng light green or yellow base- 

 color and heavily lined with brown (Mendocino Co.); the other a 

 foot or two tall and similarly marked, so fetid as to be called 

 "stink bells" (edge of San Joaquin A'alley, Contra Costa Co.). 

 Probably not in cult. — F. askahadensis, Mich. St. about 3 ft.: 

 upper Ivs. linear-lanceolate, whorled: fls. 5-8, hanging amongst 

 the uppermost Ivs., about 1 in. long, bell-shaped, pale yellow-green. 

 Cent. Asia. B.M. 78.50. G.C. III. 31 :23S; 45: 184. Gn. 61. p. 256. 

 G.M. 45:745. R.H. 1903: ISO. J.H. III. 44:293. F. S. R. 1 : 134.— f. 

 conica, Hort. Lvs. in a rosette: fls. bell-shaped, pale yellow outside 

 and bright yellow inside. Greece. — F. p6nlica, Wahl. St. tall, I H 

 ft., leafy at middle, the lvs. broadly lanceolate, lower ones opposite: 

 fls. yeiiow-green, margined and tipped red. the segms. bearing 

 nearly orbicular nectaries. Asia Minor. Gn.W, 21:407. — F. 

 tunffisia, Heldr. St. 8-10 in.: lvs. long and glaucous: fls. 4-6, bell- 

 shaped, about 1 in. across, intense dark maroon. Greece. Gn.W. 

 23:435. — F. Zdhnii, Hort. Fls. bell-shaped, rather large, brown, 

 checkered with green inside and streaked with yellow outside. 

 Greece. WiLHELM MiLLER. 



L. H. B.f 



FROELICHIA (J. A. Froelich, physician of Ellwangen, 

 Germany, monographed Gentiana in 1796; died 1841). 

 Amarantacese. About a dozen species of wooUy or hairy 

 American annuals, found chiefly in W. Indies, Mex. 

 and Brazil, scarcely planted: lvs. opposite, entire or 

 nearly so: spikes opposite, terminal; fls. perfect, 3- 

 bracted; calyx tubular, 5-cleft, hardened and spiny- 

 crested in fr. ; stamens 5, with united filaments: fr. an 

 indehiscent utricle, inclosed in the filament-tube. F. 

 floridana, Moq., has been advertised for sale in Amer. 

 It is cult, abroad. Height 1-4 ft., leafless above: lvs. 

 hnear to oblong or lanceolate: spikes 2 in. long or more; 

 fls. white and wooUy, set off by smaU blackish bracts: 

 fr. broadly winged and irregularly toothed. July-Sept. 

 B.M. 2603 (as O plolheca floridana) . Dry sandy areas, 

 Del. to Fla., and west. F. campestris, Small, is by 

 some authors considered not to be distinct. 



L. H. B.f 



FROST. Hoai- frost or white frost is ice deposited 

 upon the surface of plants or other objects. Sometimes 

 it consists of frozen dew-drops, sometimes of feathery 

 spinelike ice-crystals, but usually both formations are 

 present. The moisture from which the deposit of ice is 

 formed comes partly from the ground, partly from the 

 air, and in the case of plants, probably partly from the 

 plant itself. 



The term "black frost" is used when plants are 

 frozen without the appearance of any deposit of ice 

 upon them. It occurs when the temperature falls below 

 the freezing-point (32° F.), but not low enough to cause 

 the moisture in the air to come out in the form of hoar 

 frost. 



The term "frost," when unqualified, means simply 

 temperatures that are injurious to vegetation without 

 regard to any deposit of ice. It is in this sense that 

 the term "frost" is used in this article. 



Degrees of frost. 



With respect to the effect of frost on vegetation, the 

 Weather Bureau recognizes three degrees of frost — 

 hght, heavy, and kiUing. A light frost is recorded when 

 only the tenderest plants are injured; a heavy frost, 

 when the injury to tender plants is more marked and 

 the hardier plants are damaged; and a kiUing frost, 

 when the staple products of the region are injured 

 severely or are killed. When no deposit of frost occurs 

 and the temperature of the air as indicated by the 

 thermometer falls during the night to 32°, a killing 

 frost is recorded also. Frost charts and frost tables, 

 published by the Weather Bureau, are based on the 

 records of killing frosts only. 



How plants are injured by frost. 



When ice appears on the leaves or blossoms of the 

 plant, it is evidence that the temperature of the plant 

 is at or below the freezing-point; but if the temperature 

 does not go below 32° F., or does not remain at that 

 point too long, httle injury will result to any temperate- 

 zone plants. In fact, the phenomenon that we usually 

 have in mind when we speak of killing by bw tempera- 

 ture occurs only when ice forms within the tissue. Care- 

 ful observers have found that the ice formed in the 

 tissue is nearly always in the interceUular spaces, the 

 water being withdrawn from the cells to form these 

 crystals. Whether the withdrawal of water from the 

 cell is the cause of death or is merely associated with it, - 

 is not certain. In case of winter dormant tissue, that 

 is verj- resistant to low temperature, the injury at a 

 given temperature is much greater when the tempera- 

 ture-fall is very rapid. In the case of a few tissues, like 

 ripe apples and pears and leaves of Agave americana 

 and of lettuce, the rapidity of thawing influences the 

 extent of injury at the highest killing temperature of 

 the tissue. However, it is not a determining factor, 

 since, if the temperature be carried somewhat lower, 

 the tissue will kill regardless of the rate of thawing. 



