RONDELETIA 



ROOT -GALLS 



1545 



easily at any time, and these may be grown in pots for 

 a season. Barring the tendency to stooling, they do 

 well planted out. Sandy loam and leaf-soil is the best 

 compost, and a warm greenhouse, with sunshine, fur- 

 nishes the best conditions. t. D. Hatfield. 

 A. Fls. red. 

 B. Jyvs. opposite. 

 odor&ta, Jacq. (RondeUtia specidsa, Lodd.). Lvs. 

 ovate, nearly sessile: clusters 10-30-fld. : fls. crimson to 

 brick-red, with a conspicuous yellow throat; lobes 



2143. Rondeletia cordata (X 34). 



elliptical to roundish. Cuba. Mex. B. 2:53. B.M. 

 3953. B.R. 22:1905. F.C. 1:36. L.B.C. 19:1893. P.M. 

 2:242; 16:354. R.H. 1891:522 (throat not conspicuously 

 yellow). 



BB. Leaves in 3^s. 



andmala, Hort. Figured in J.H. III. 35:251 with 8 fls. 

 in a cluster, the fls. % in. across, with roundish lobes. 

 The color is said to be coral-red or deep scarlet and the 

 throat is presumably yellow. Habitat (?). Imperfectly 

 known. 



AA. Fls. pink to white. 

 B. Base of lvs. more or less cordate. 



cordata, Benth. (Jt. corddta, Planch. B. tJiyrsiflora, 

 Hort., not Roth.). Fig. 2143. Lvs. ovate, acuminate, 

 cordate; generally said to have pink or flesh-colored fls. 

 with a yellow throat (as in P.S. 8:754, page 13), but in 

 R.H. 1878:230 they are shown as pure white. Guate- 

 mala. Franceschi says it is native to Mexico. 



BB. Base of lvs. not cordate. 

 c. Corolla-lohes ovate: stipules broadly ovate. 

 amoena, Hemsl. (B. amoena, Planch.). Lvs. elliptic, 

 broader than in H. gratissima, and shorter acuminate, 

 2-5 in. long: fls. rose-pink, with a conspicuous yellow 

 throat. Guatemala. F.S. 5:442. Seti ulso B. versicolor 

 in supplementary list. 



cc. Corolla-lobes ohcordate: stipules subulate. 

 gratissima, Hemsl. (B. gratissima, Linden). Lvs. 

 oblong -elliptic, 1-2 in. long, short -petioled, mostly 

 rounded at the base: fls. with a bright rosy tube, the 

 lobes fading from pale rose to whitish ; throat not con- 

 spicuously yellow. Trop. Amer. I.H. 28:424. F.S. 

 15:1570 (corolla-lobes often obovate; stipules narrowly 

 ovate). Gt. 490 (as B. elegantissima). 



The following species would probably be desirable additions, 

 as they represent other colors than the above: R. Americana, 

 Linn. Wliite-fld. West Indies and S. Amer.— iJ. Bdckhousii, 

 Hook., a pink-fld. species from trop. Amer., is easily distin- 

 guished from those mentioned above by the much longer calyx- 



lobes, which are pink. B.M. 6290. — R. Ptirdiei, Hook., a beau- 

 tiful pale yellow-tld. species from Colombia, has a great pyra- 

 midal cluster 5 in. across and 4 in. deep, with an astonishing 

 number of fls., perhaps 150-200 in B.M. 5(509. — R. versicolor. 

 Hook., is referred to R. amoena by Index Kewensis but seems 

 distinct. The fls. are said to be "remarkable for their play of 

 colors; the tube is yellow; the limb in bud deep rose-color, 

 changing when they expand to pale rose and then to white, 

 with a yellow disk, and having a two-lobed green spot in the 

 center from the color of the stigmas, which protrude a little 

 beyond the mouth." B.M. 4579. )jy_ jyj^ 



ROOT CELLARS. See Storage. 



ROOT-GALLS. Abnormal enlargements often appear 

 on the roots of plants. These enlargements are much 

 more frequent than is generally supposed, but from 

 their position under ground are rarely observed. From 

 an economic standpoint they have not received the 

 attention that they merit. 



Although the terra root-gall is usually applied to the 

 abnormal enlargement of roots due to insects and other 

 animal organisms, it has a much wider application as 

 used by most plant-growers. The presence of nodules 

 or local enlargements on the roots of plants has been 

 discussed by different authors under the names root- 

 galls, root-knots, root-swellings, etc. In cases in which 

 the cause of the nodules of hypertrophied tissue is 

 known, special names have been assigned to the enlarge- 

 ments. Thus the gall formed by the eel-worm (Uetero- 

 dera radicicola) is known as the nematode root-gall 

 (Fig. 2144) ; the enlargement on the roots of cabbage and 

 related plants by the myxomycete (Plasmodiophora 

 Brass iete) is called club-root; the swellings on the roots 

 of the peach, apricot and many other plants, which are 

 of characteristic appearance and usually appear at the 

 crown of the plant, are known as crown-gall. Root 

 tubercles are small gall-like bodies found on the roots 

 of many leguminous plants. They are symbionic in 

 nature, the organism causing them being helpful to the 

 plant. See Legumes. 



Abnormal root enlargements are due to the following 

 causes: (1) animal parasites, as in the nematode root- 

 gall (Fig. 2144), the galls formed on the roots of the 

 grape by the phylloxera, and the galls frequently 

 observed on the roots of our indigenous ceanothi; (2) 

 vegetable parasites, as in the club-root and the crown- 

 gall (Fig. 2145); (3) mechanical injury, causing exces- 

 sive callous development, root-burls, etc. 



In addition to the above, the causes of these enlarge- 

 ments are oftentimes obscure or unknown. The form 



2144. Root-galls due to nematodes— Tomato roots. 



of crown-gall on the apple, blackberry and a large 

 number of other plants is as yet unknown so far as 

 cause is concerned. It may be caused by a similar 

 organism as that causing the crown-gall on the peach 



