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DAHLIA SCAPIGERA. 



• (Scape-bearing Dahlia.) 



LINNEAN SYSTEM. ^ ^ NATURAL ORDER. 



SYNGENESIA SUPERFLUA. COMPOSITE — ASTEROID E^. 



GENERIC CHARACTER. 



Dahlia. (Cav.) Capitulum radiatum, floribus radii ligulatis fcemineis neutrisve, disci 

 tubulosis 5-dentatis. Involucrum duplex, exterius squamis foliaceis 1-serialibus circiter 5 patulis 

 reflexisve, interius, squamis 12-16 subbiserialibus longis apice membranaceis basi crassiusculis et 

 inter se coalitis. Receptaculum planum paleaceum, paleis membranaceis oblongis indivisis. 

 Styli rami erecti aut subincurvi crassi extus piliferi. Antherce ecaudatae appendiculatse. 

 Achamium oblongo-obovatum obcompressum epapposum apice obsolete bicorne. — Herbse 

 Meocicanae grandes. Folia opposita pinnati-partita- rarius bipinnati-partita, segmentis ovatis 

 acutis serratis. Radices fasciculatae, aliis cylindricis, aliis oblongo-tuberculatis. Rami apice 

 elongati nudi 1-cephali. Capitula versicolora, disco nempe luteo, radio purpurSo roseo albo aut 

 flavo. — De Cand. 



Head radiated, flowers of the ray ligulate, female, or neuter, those of the disk tubular 

 5-toothed. Involucre double, exterior one of about 5 leafy scales in a single series, spreading or 

 reflexed ; the interior one consisting of from 1 2 to 1 6 scales arranged rather in two series, long, 

 membranaceous at the apex, a little thickened at the base, and united with each other. Receptacle 

 flat, chaffy, scales membranaceous, oblong, undivided. Branches of the style erect or somewhat 

 incurved, thick, externally hairy. Anthers ecaudate, appendiculate. Seed oblong-obovate, 

 obcompressed, without pappus, obsoletely 2-horned at the apex. — Fine Mexican plants. Leaves 

 opposite, divided in a pinnate, more rarely in a bipinnate manner, segments ovate, acute, serrated. 

 Roots fasciculate, some cylindrical, others oblong-tubereulate. Branches elongated at the apex, 

 naked, 1-headed. Heads various in colour ; namely, with a yellow disc, and purple, rose, white, 

 or yellow rays. 



SPECIFIC CHARACTER. 



D. scapigera; caule glabriusculo striate ; foliis pinnati-partitis ; segmentis ovatis dentatis 

 basi insequalibus ; ligulis foemineis fertilibus ; pedunculis gracilibus longissimis. 



Stem rather glabrous, striated ; leaves divided in a pinnate manner ; segments ovate, toothed, 

 unequal at the base; florets of the ray furnished with styles, fertile ; peduncles, slender, very long. 



Georgina scapigera. — Link et Otto. 



Descr. — Plant about two feet high, of slender habit, throwing up numerous stems, for the 

 most destitute of pubescence. Leaves variable in form ; the lower ones having the terminal 

 segment ovate, while in the upper ones it is generally long, narrow, and linear. Peduncles very 

 long, slender, glabrous, sometimes standing singly, more frequently in pairs, but generally in 

 VOL. III. NO. XXXII. OCTOBER, 1839. Q 



