lS:Ui 



LKITNKKIA 



LEMNA 



fls. niilunit iH-rianlh, with ;> IJ stamens: pistilhvtc 

 ixwsistinp of a short-stalk^l piiln'siviil ovary witli 

 small ijlanii-frinmHl scales at tlie liase: styli' slender: fr. 

 :in oliloiiK mllut^^l eompresseil. l-setslinl ilriiiie. ()iie 

 Slavics ii\ 1-la. aiul Texas to S. Mo. Tlie exeetHlintily 

 light wiHxl IS oeeasionally used for the floats of lisliinj;- 

 m-ts. llanly as far iiortli as Mass.: it prows be.st in 

 IH'.Hty. humid or swampy soil. I'rop. readily by suekers 

 whieh are freely produeiil in establislied plants. 

 L. floridina, t'hapm. Oeeasionally to 20 ft.: Ivs. 

 elliptie-laneeolate to laneeolate, aeute or aeuminate, 

 pulx'seeiil below, 4-<) in. long: staminate <'atkins 1 1 '.i 

 m. lonn: pistillate smaller and slenderer: frs. 1 I, -'liii. 

 long. S.S. 7::v«l. 11.1.11:1041. Hep. Mo. Hot. Card. 

 l>:3»)-44.— The plant h;is no elaim to ornamental 

 qualities, but is botanically intercstiiifi. 



Ai-KHKi) Uehdeh. 



LEMAIREOCfeREUS il^-mairo's Cereus). Caclncai. 

 Isually larg<- Ines or shrubs (one si)ecios prostrate). 



Stems and branrhes stronnly ribbed and with numer- 

 ous stout spines: fls. diurnal, ine(lium-si/.e<l: fr. covered 

 with clusters of spines (finally falling off as the fr. 

 ripens 1, edible.— Species V.i. This is one of the most 

 imjHirtant genera of the C'ereus prou)!. Some, and jur- 

 hai>s all. s|MM-ies are of great e<-ononnc value: some are 

 widely planto<l in the tropics for their dehcious fr. 

 Some 8 species are in cult. 



A. Plants prostrate: fls. yellow. 

 erOca, Brit. & Rose {C'ereus eriica, Brandegee). 

 Stout, usually simple sts. prostrate, radiating from a 

 center, dying at one end and advancing at the otlici', 

 rooting on the unfler surface, '.i-T in. diam., densely 

 anne<l with spines: lis. 4-.") in. long, with a slender tube, 

 reix}tte<l to be yellow: fr. globular, 2 in. diam., some- 

 what spiny. Common on the sandy plains of S. Low. 

 Cahf.— <Jf very peculiar habit, suggesting large cater- 

 pillars creeping along over the ground. This is espe- 

 cially noticed from the way they piiss over obstructions 

 or the bodies of other individuals. First the head or 

 growing end is raisc<l U[) over the object and passes 

 down on the other side; then, by llie dying back at the 

 rear, the plant finally .seems to have actually passed over 

 the ob.struction. This cactus is usually planted wrong 

 in collections since most ganleners insist on |)lacing it 

 erect in a pot; but as it i.s con.stantly dying at base, it 

 must sooner or later die. It ought to be laid flat at, one 

 end of a long box and allowed to creep toward the 

 other end. There seems to be no record of this species 

 having flowered in cult. 



AA. Ptant-s usually tall and erect. 

 B. AreoleJi with l/rown wool, more or less glandular. 



c. Ribs 12-16. 

 Thtirberi, Brit. & Rose (C'ereus Thurheri, Kngelm.). 

 Several sts. arising from the same root, becoming 1()-15 

 ft. high; ribs l.'i-l(i, very slightly iiromineni: spines 

 7-16, slender and rigid: fls. greenish white: fr. globose, 

 1-3 in. diam. S. W. Ariz, southward thnjughout Low. 

 Calif., and to Sinaloa. 



cc. Ribs 6-8. 

 queretarensis, Brit. & Rose; (C'ereus querctarinsis, 

 \Vi4>. . .\rlx)resf:ent, with a trunk aVjout .'J ft. high by 

 abriUt 14 in. diam.: the rnuch-brandied crown has a 

 diam. of 12-16 ft., the total height of a plant being about 

 2f) ft.: bninches dark green, in young growth frecjuently 

 of a peculiar violet-brown; ribs 6 7, sr-p,irateil by sharp 

 Kr'Kjv«'S<, which later become much flattened, and the 

 Ht. wtn.'tf-quently more cylindrical; areoles depn^.ssed, 

 dark brown; nulial spines (V-O, the lower ones long(!st, 

 about \]/i in. long; w^ntrals 4 (oft<-n but 2), reaching 

 1 5^ in. : flu. numerous from the upper part of the 

 branrh»«, ab<<ul 4-.'!> in. long; fr. yellow to red, about 2 

 in. long, wjverfxl with dark yellow to brown spines, 

 about 1 in. long, and bulbos<- at the b;i.se. .Mex. 



lut. .\reohs with gray wool, ikiI <it all </liiii(h(l(ir. 

 c. The areuUs of Ihf omry aiiil Jl.-lulte hearing long flat 

 bristles along with the sjiines. 

 stellatus, Brit. A- Hose [Clnua sldlalus, I'feilT.). 

 Stout, with few ujjrighl branches, 10 \^^ ft. liigh: ribs 

 7-l.'>: areoles ' ^-1 in. a|)art ; raili;U spines S 10; centrals 

 .'15: fls. from near the ends of the branches, about 2 

 in. long, light pink: fr. globvdar, I'j in. diani., covered 

 with clusters of deciduous spines, edible. — Sold in 

 markets of S. Mex. Hare in collections; often confused 

 with Hathbunia sonorensis and L. Trelrosei. 



cc. The areoles of the ovary and fl.-tube not bearing long 



bristles. 



D. Fls. long and slender. 



gummdsus, Brit. & Rose {Cereus Cumengei, Web. 



C. giininio.tiis, Kngelm. C. gumniA'^vs, Hort.). More or 



le.ss branched, at first erect, then clambering or with 



some of the branches procumbent: ribs 7-i(: spines 



rigid, 15 or 20: lis. purple, 4-5 in. long: fr. spiny, scadet, 



slight ly aci<l, edible. Common in Low. Calif. — This 



species does not grow easily in hothouses nor does it 



flower readily. It is a very important fr. to the poor 



of Low. Calif. 



DD. Fls. rather short. 



K. .\r<i}l<s very close together, often running together. 



Dumortieri, Brit. & Rose (C'ereus Diiniortilri, Salm- 

 Dy<'k). Often large tree with a trunk 2 ft. diam. and 

 hundreds of ujiright branches: branches strongly U- 

 ••mgled: areoles closely set; spines numerous, needle- 

 like, the longer ones 1'2 in- long: fls. .small for the 

 genus, 2 in. or le.ss long, white. Ont. Mex. — Usually 

 only small plants seen in cult. 



EE. Areoles more distant. 

 griseus, Brit. & Rose (C'ereus grlseus, Haw. C. 

 ebiirneus, Salin-Dyek). Tall tree, 25 ft. or more high, 

 more or le.ss branched: ribs 7-12, broail: spines 10-15: 

 fls. purplish: fr. globular, covered with deciduous clus- 

 ters of spines, edible. — Commonly cult, in Trop. .\mer. 

 for its frs. It is especially highly 

 prized in Mex. 



Weberi, Brit. & Rose (Cereus 

 Weberi, Coulter. Cereus candela- 

 brum, Web.). Trees, 30 ft. or more 

 high, with a regular candelabra form 

 of branching, containing hundreds 

 of erect branches: spines stout, 10 

 or more on a cluster: fls. lateral, 

 white, about 5 in. long: fr. unknown. 

 — This species, although not the 

 tallest, is probably the largest in 

 the whole cactus family. It is found 

 in the hot valU'ys of S. Mex. where 

 it literally forms forests. The fr. is 

 not well known and the relation- 

 ship is still uncertain, j j^' Rose. 



LEMBOTROPIS NIGRICANS: O/'isM 

 nif/nc'in.^, 



LEMNA (old Grei'k name, prob- 

 ably referring to the swampy 

 habitat). Lemnacea'. Duckweed. 

 Duck's- Meat. Minute floating 

 plants, like fragments of green, often 

 found in standing pools and some- 

 times introduced into aipiaria and 

 lawn basins. 



The Lemnacea^ comprises the 

 minutest of flowering plants, some 

 30 Rjjecies in 4 genera: Lemna, Spiro- 

 dela, Wolffia, Wolfliella. They are 

 2130. Duckweeds, widely ilistributed in temperate, 

 Lemna minor. subtropical and tropical regions. 



(.Vlui^h i^nlargcd) They often cover the water of 



