394 



CRASSULA 



CKAT^GUS 



but cultivation probably changes the number of parts 

 not infrequently. Crassulas are herbs or shrubs, rarely 

 annuals, usually thick and fleshy: Ivs. opposite, rarely 

 stalked, often grown together at the base, entire or with 

 a cartilaginous margin: fls. small, white, rose, or rarely 

 yellow, usually in cymes, rarely in heads. For C. coc- 

 cinea and jasminea, see Rochea. \\ T > ]\j < 



Crassulas are greenhouse plants requiring a dry atmos- 

 phere during the resting period. While making growth, 

 they may be treated like other greenhouse plants in the 

 way of watering, placing them in the lightest and airiest 

 part of the house. The pots must be drained so that any 

 surplus moisture will easily pass through. The soil 

 should consist of sand, loam, broken brick, and a very 

 small quantity of leaf-soil or thoroughly rotted cow- 

 manure. Propagation is usually from cuttings. Some 

 of the species, such as C. falcata, do not give much 

 material for this purpose, and they should, there- 

 fore, be headed over and the tops put in dry sand 

 in the spring, allowing water only when they show 

 signs of shrivelling. The cut -over plants should 

 be encouraged to make side shoots, which may be 

 rooted after they are large enough. 



Cult, by G. W. OLIVER. 

 A. Floral parts normally in 5's. 



B. Lvs. petioled. 



cordata, Soland. Height 1-3 ft. : stem shrubby: Ivs. 

 flat, wide, stalked, cordate, obtuse, entire, glabrous, 

 spotted above : cymes panicle-like : fls. reddish, some- 

 times pure white. Winter. Closely allied to C. spathu- 

 lata. 



spathulata, Thunb. Glabrous herb : stem somewhat 

 shrubby, decumbent, branching: Ivs. stalked, roundish, 

 crenate, glabrous, shining above : corymbs panicle-like: 

 fls. rosy; petals acute. L. B. 

 C. 4:359 as C. cordata. 

 Not advertised for sale, but 

 likely to be cultivated as C. 

 cordata. 



BB. Lvs. not petioled. 

 c. Foliage glaucous. 

 falcata, Wendl. Height 

 3-8 ft. : Ivs. grown together 

 at the base, thick, glaucous, 

 oblong, falcate': fls. small, 

 numerous (50 or more), in 

 a crimson, rarely white, 

 dense, terminal corymb : 

 corolla tube % of an in. long, 

 as long as the limb or 

 shorter. B.M. 2035. 



cc. Foliage not glaucous. 

 lactea, Soland. Height 1-2 

 ft. : stem shrubby, branch- 

 ing, tortuous below : Ivs. 

 ovate, narrowed and grown 

 together at the base, gla- 

 brous, spotted along the 

 margin : cymes panicle-like, 

 many-fld. : fls. white, small. 

 Winter. B.M. 1771. L.B.C. 

 8 : 735. A free - flowering 

 window plant of easy cul- 

 ture. There is a form with 

 variegated leaves. 



AA. Floral parts in 4's. 



quadrifida, Baker. Fig. 

 574. Perennial: Ivs. oblong- 

 spatulate, the upper ones 

 rounder, decussate: fls. with 

 their parts in 4's, panicled, 

 white, tinged red. ^. ]yj 



574. Crassula quadrifida. 

 (XH-) 



CRAT.EGUS (ancient Greek name, derived from kratos, 

 strength, on account of the hardiness of the wood ) . Rosd- 

 cece, suborder PbmecK. HAW. HAWTHORN. Shrubs or 

 small trees, usually spiny: Ivs. alternate, deciduous, 

 stipulate, serrate, often lobed or pinnatifid: fls. white, in 



some varieties red, in corymbs, rarely solitary; petal - 

 and calyx-lobes 5; stamens many, rarely less than 10; 

 styles 1-5 : f r. a drupe-like pome, with 1-5 1-seeded bony 

 stones. About 70 species, in the temperate regions of 

 the northern hemisphere, most abundant in N. America. 

 Hardy ornamental shrubs and trees, mostly of dense and 

 low growth, with handsome foliage, turning, in most 

 species, to a brilliant coloring in the fall; many have 

 very decorative frs., and also handsome fls. Some of the 

 best, with showy frs., are C. Crus-galli, C. Lavallei, 

 C. cordata, C. pinnatifida major, C. mollis, but the frs. 

 of the last drop very early, while in most of the others 

 the frs. remain a long time on the branches. Some varie- 

 ties of C. monogyna have very decorative fls. ; also C. 

 mollis, C. Cms-galli and others are handsome in bloom. 

 For the S. states, C. cestivaUs and the blue-fruited C. 

 brachyacantha are among the most decorative. Well 

 adapted for hedges are C. monogyna, C. Oxyacantha, 

 C. Crus-galli, C. cordata and many others. The Haw- 

 thorns grow in almost any soil and position; best in a 

 rich, loamy, somewhat moist one, and also in strong clay. 

 Prop, by seeds, sown in fall or stratified; before stratify- 

 ing, most of the pulp may be removed by laying the frs. 

 in shallow piles and allowing them to decay. Then they 

 are mixed with sand or sifted soil and buried in the 

 ground or kept in boxes in a cool cellar. Some species, 

 as C. cordata, C. coccinea, C. Crus-galli, germinate the 

 first year and are sown in spring, while others, especially 

 C. Oxyacantha and its allies, do usually not germinate 

 until the second year, and may be kept stratified until 

 the following fall or the second spring. If sown at once, 

 the seed-beds must be heavily mulched during the first 

 summer to prevent drying. The young plants should not 

 be allowed to remain over one year in the seed-beds, as 

 they form long tap-roots and are then difficult to trans- 

 plant. Varieties and rarer kinds are easily budded or 

 grafted on seedling stock of C. Oxyacantha, or other 

 common strong-growing species. 



Index : aceri folia, 13 and suppl. ; apiifolia, 14 and 

 suppl. ; Aronia, 18; Azarolus, 18; Carrieri, 7; coccinea, 

 3; cordata, 13; Crus-galli, 5; Douglasi, 12, 10; flava, 2; 

 Lavallei, 7; leucophlceos , 9; lucida, 5; macracantha, 10; 

 mollis, 4; monogyna, 16; nigra, 21; odoratissima, 19; 

 orientalis, 19: Oxyacantha, 15, 1C; parvifolia, 1; pinnati- 

 fida, 17: populifolia, 13 and suppl. ; prunifolia, 6 ; punc- 

 tata, 8; pyrifolia, 9; sanguiiiea, 11; siibvillosa,^; tana- 

 cetifolia, 20; tomentosa, 9: uniflora, 1. 



A. Foliage of the flowering branches not at all or very 



slightly lobed; no veins going to the sinuses. 



B. Fls. 1-3, rarely more. 



1. unifldra, Moench (C. parvifblia, Ait.)^ Dense, low 

 shrub, with numerous slender spines, rarely spineless, 

 3-8 ft.: Ivs. on short not glandular petioles, cuneate, 

 obovate or oblong-obovate, irregularly or doubly crenate- 

 serrate, pubescent on both sides, at length glabrous 

 above, %-!% in. long: calyx pubescent, with large ser- 

 rate lobes: fr. pyriform or globose, yellow, /-sin. across, 

 with 2-5 stones. May, June. N. Jersey to Arkansas and 

 Florida. 8.8.4:191. 



2. flava, Ait. Shrub or small tree, to 25 ft., usually 

 very spiny: Ivs. on short glandular petioles, cuneate, 

 obovate, glandular-dentate, pubescent, at length glabrous 

 and shining above: fr. globular or pyriform, greenish, 

 yellow or red, % in. across. Va. to Florida. S. 8. 4:189. 

 B.R. 23 = 1932,1939. 



BB. Fls. in 6-many-fld. corymbs. 



c. Lvs. on slender, often glandular petioles, usually 

 broadly ovate and truncate at the base, slightly 

 lobed: calyx lobes dentate. 



3. coccinea, Linn. SCARLET THORN. Shrub or tree, 

 rarely to 25 ft., with short spines: Ivs. broadly ovate, 

 sharply doubly serrate, nearly glabrous beneath, spar- 

 ingly appressed-pubescent above, 2-3 in. long: corymbs 

 usually slightly villous: fr. red, globose or oval, %-% in. 

 across. April, May. Newfoundland to Florida and 

 Texas, west to Manitoba. 8.8.4:180. Em. 493. B.M. 3432. 

 There are a number of allied forms which have been 

 considered usually as mere varieties, but may be per- 

 haps distinct species. None of them, however, surpasses 

 the true C. coccinea in decorative value, and they are 

 only of botanical interest. 



