TJMBELLIFER^^. 146 



the Andean and antarctic regions of America, woody at the base, 

 rigid, with 3-5-sect or 3-5-fid leaves, often spinescent, with petioles 

 often dilated to scarious sheaths. The flowers, not unfrequently 

 unisexual, are in simple umbels. Hennas, from the Cape, is analo- 

 gous to Mulmum, It has its fruit, succeeding flowers whose sepals 

 are well developed and whose petals resemble staminal filaments. 

 They are perennial herbs with rosetted, entire, hairy or woolly leaves, 

 and with long simple or ramified axes terminating in umbels appa- 

 rently compound. It should be observed that in these two genera, 

 as also in the three following, the distribution of the primary ridges 

 is such that the median and the two intermediaries are dorsal, while 

 the two lateral, instead of being marginal, are relegated (sometimes 

 very far) to the interior face of the mericarp. 



Huanaca and Diposis are also closely allied to Mulinum. In the 

 latter, of which a genus Asteriscium has been made, the leaves are 

 those wrongly called radical, lobed or 



variously divided, and the inflorescence AstenScium {Gymnophyton) 



is a simple many-flowered umbel with robustum. 



an involucre of small bracts. The 

 fruit is much compressed perpendicular 

 to the partition, similar to that of Mu- 

 linwn, with a narrow commissure and 

 mericarps dorsally concave. Gijmno- 

 phyton (fig. 168) is Asteriscium whose 

 hard l)ranched axes are without true 

 leaves ; but the inflorescences are um- 

 bels in which the interior flowers are 

 fertile and the exterior male with longer ^^' ^ " ^"^ ^'^' 



pedicels. The true Diposis, such as 



D. saniculcefolia, is to the preceding what Micropleura is to other 

 genera of Hijdrocotijle. In fact the ramified inflorescences bear, 

 below a female flower of sessile fruit, two lateral pedicels which 

 terminate in a flower generally male or sterile. It is moreover a 

 glabrous herb, with radical divided leaves and disklike carpels. All 

 these plants inhabit extratropical South America. Huanaca is a 

 caespitose herb with leaves mostly radical. In the true Huanaca of 

 South America, they are palmatisect, and the floriferous axes are 

 ramified. In Canahua, which are Mexican, the leaf is pinnatisect or 

 pinnatipartite, and the umbel is simple supported by a long slender 



VOL. VII. L 



