243 



A RT. XXXIV. — A Monograph of Streptopus, with the Description of a 

 new Genus note first separated from it. By David Don, Esq., Libr. 

 L.S., Prof. Bot. King's Coll. Loud. 



" The genus Streptopus was first proposed by the elder Richard in Michaux's ' Flo- 

 ra Boreali-Americana,' and was intended to include not only the Uvularia amplexi- 

 folia of Linnasus, l)ut two other plants therein d&scribed for the first time, namely, S. 

 roseus and lanuginosus. The two last are exclusively confined to North America, 

 while the first is coJumon to Europe and America." — p. 525. 



In Streptopus amplexifolius, which Mr. Don considers as the type 

 of the genus, are united the following characters : — a six-leaved cam- 

 panulate perianth with deciduous sepals, which have " a nectariferous 

 furrow at their base ; erect sagittate anthers, with short dilated fila- 

 ments ; three separate stigmata;" and a berry-like pericarp with poly- 

 spermous cells. From the genus thus characterized the author has 

 found it necessary to remove Strept. lanuginosus, on which he founds 

 a new genus. The genus Streptopus still comprises three species, — 

 Str. amplexifolius, roseus, and simplex : the last species is from the 

 Himalayas, and was first described by the author in his ' Prodromus 

 Floraj Nepalensis.' 



" These plants have all a peculiar habit, cylindrical leafy stems, hroad amplexicaul 

 leaves, glaucous beneath, and axillary, solitary, mostly single-flowered peduncles, which 

 in amplexifolius are curiously twisted at their middle. The genus undoubtedly be- 

 longs to the Smilacese, and is nearly allied to Convallaria and Smilacina, but is essen- 

 tially distinguished from both by its distinct sepals, each furnished with a nectariferous 

 furrow, separate stigmas, and polyspermous berry. With Uvularia it accords in habit, 

 and in its solitary, axillary, campanulate flowers ; but its innate anthers, furnished 

 with short filaments, baccate pericarpium, and noncarunculate seeds, remove it widely 

 from that genus." — p. 526. 



Of the new genus, Prosartes, the author observes : — 



" This very natural genus, as I have already stated, forms the transition from the 

 Smilaceae to the Melanthaceae, and possesses several characters in common with Strep- 

 topus and Disporum. From the former genus it is essentially distinguished by its 

 much more lengthened filaments, binary pendulous ovula, and terminal umbellate in- 

 florescence ; [and it differs from Disporum] in its innate anthers, nearly concrete styles, 

 and pendulous seeds." — ^p. 53J. 



The genus Prosartes includes two species, — Pros, lanuginosa, from 

 North America, the Streptopus lanuginosus of Michaux; and Pros. 

 Menziesii, also from North America, named after the late Mr. Men- 

 zies, and now first described. 



" In the Smithian Herbarium there is a single specimen of this highly interesting 

 plant gathered by my venerable friend Mr. Menzies on the north-west coast of Ame- 

 rica in the voyage of discovery under Vancouver, to which he was attached in the ca- 



2 Y 



