safford: notes on dahlia 369 



bad condition, owing both to the difficulty of drying succulent 

 plants like dahUas. which wilt as soon as gathered, and to the 

 injury of the flower heads by insects. 



Dahlia popenovii Safford, sp. nov. Tepeacocoxochiil (Nahuatl) ; Papalotl, 

 Tunaita (Guatemala). 



A herbaceous plant about i meter high with fascicled, fleshy roots 

 and slender, erect, hollow, striated, purplish stems glabrate near the 

 base and sparsely clothed above with minute, whitish, woolly hairs. 

 Leaves membranaceous, opposite with the bases of the petioles con- 

 nate, as in the rest of the genus, the lower ones (lacking in the type) 

 described as bipinnate; the upper ones simply pinnate, usually 3-foUo- 

 late, or simple and deeply 3-lobed, with the leaflets or lobes decurrent 

 on the rachis and winged petiole, sparsely clothed with short, stiff 

 hairs; leaf-Uke bracts of the inflorescence simple, laceolate, acuminate, 

 sessile; leaves of young seedlings simple, broadly ovate, with the base 

 decurrent on the slender petiole. Inflorescence more or less corym- 

 bose, with the flower heads borne on long slender, petioles, erect or 

 slightly curved at an thesis, at length recurved or nodding; peduncles 

 12 to 14 cm. long bearing one or two bracts, sometimes with a shorter- 

 peduncled head issuing from the axil of the bract. Flower heads 6 

 to 9 . 5 cm. broad, those of the type with bright scarlet or cardinal rays 

 and yellow disks ; outer involucre calyx-like, as in the rest of the genus, 

 composed of 5 spreading or recurved spathulate-oblanceolate bracts; 

 inner involucre composed of about 10 erect, diaphanous, oblong scales, 

 rounded at the apex, enlarging after anthesis; ray florets 8, sterile, 

 widely spreading, rounded and abruptly pointed at the tip, revolute 

 or turning backward along the margins as in forms of the "cactus" 

 type of cultivated dahlias; disk florets hermaphrodite, tubular; mature 

 achenia 12 or 13 mm. long, concealed by the thin, diaphanous paleae 

 borne on the disk, these resembling the scales of the inner involucre 

 and almost equal to them in size. 



Type in the U. S. National Herbarium, no. 1010584, collected near 

 San Lucas, Department of Zacatepequez, Guatemala, at an approximate 

 altitude of 6600 feet, October 21, 191 6, by Wilson Popenoe (no. 682). 



This handsome species, which is probably an ancestor of the hybrid 



Dahlia juarezii, from which the "Cactus Dahlias" of our gardens have 



been derived, is named in honor of its discoverer, Mr. Wilson Popenoe, 



of the Office of Foreign Seed and Plant Introduction. It is represented 



by a single specimen, and by several seedlings propagated at Yarrow, 



Maryland, from seeds collected by Mr. Popenoe. In Mr. Popenoe's 



field notes he writes as follows : 



Antigua, Guatemala, October 23, 1916. — On my way back from 

 Guatemala City to this place I collected some wild dahhas about 2 

 kms. above Santa Lucia, at an approximate elevation of 6600 feet, 

 where the plants were most abundant. I have not seen them as low 



