MR. J. MIERS ON TWO GENERA OF PLANTS FROM CHILE. 145 



marcescent but persistent floral envelopes is about f of a line long. The branchlets and 

 peduncles are sparsely beset with very short patent hairs, bearing a resinous gland at their 

 summit ; these are different from the hairs of the leaves, bracts and calyx, which are simple, 

 pointed, and spring out of elevated tubercles. 



I found this plant, of which I was only able to collect a single specimen, in January 

 1825, in the main valley, on the eastern side of the great Cordillera, upon the road lead- 

 ing from Mendoza to Aconcagua, at a spot near the Estero de Santa Maria, which falls 

 into the river Tunuyan, about three leagues above the Punta de las Vacas. 



The second plant I have to record is a nearly aphyllous shrub, with straight, erect, 

 virgate branches, terminating in spines, and evidently belongs to the Bignoniacece, 

 although in many points it varies from the usual structure of that Order. In that family 

 the ovarium, formed constantly of two carpels, is generally bilocular, with ovules com- 

 monly ascending or horizontal, attached to the margins of the dissepiment : its fruit is 

 usually a long capsule, more or less woody, 2- or spuriously 4-celled; the seeds are 

 numerous, generally winged, always much compressed, and their exalbuminous embryo 

 presents broad foliaceous cotyledons, cordate at both extremities. In the present instance 

 the ovarium is simply bilocular, with a few ovules suspended on the two faces of the thin 

 dissepiment ; the fruit is a small oval drupe, containing a single osseous indehiscent nut, 

 which is 1-celled by abortion, and contains only a single pendulous seed that entirely fills 

 the cavity : this is therefore quite apterous, oval, with a small thick superior radicle, and 

 two plano-convex fleshy cotyledons, a structure quite anomalous in the Order. 



I found this plant in the year 1825, upon the skirts of the eastern declivity of the 

 Cordillera, near Mendoza, on the margin of the desert tract called " La Travesia," where 

 it was also found by Dr. Gillies. I have proposed for it the generic name of Oxycladus, 

 from blug, acutus, and xKubog, ramus, in reference to its spiny habit. 



It is evident, from the facts just stated, that this genus does not conform with any of 

 the characters that mark the tribes into which the Order has been divided by botanists. 

 The genera that most nearly approach it in habit are the Catophractes of Don, figured in 

 the 18th volume of the Society's Transactions, plate 22, and the Rhigozwni of Dr. Burchell, 

 both of which are spinose shrubs from South Africa ; but these have both large yellow 

 flowers, and the seeds of the latter agree with the characters of the true Bignoniece. It 

 will therefore be necessary to place Oxycladus in a distinct tribe, and the Order may hence 

 be divided into the following sections. 



Tribe 1. Bignonie2E. Capsule dehiscent, 2-celled, 2-valved, with numerous winged com- 

 pressed seeds attached to both sides of the dissepiment; embryo with flattened 

 foliaceous cotyledons. 



Tribe 2. Crescentie^. Fruit drupaceous, woody, 2- or many-celled, with numerous 

 winged or compressed seeds ; embryo with compressed fleshy cotyledons. 



Tribe 3. Oxyclade^. Fruit drupaceous, containing a single 1-celled, osseous, inde- 

 hiscent nut, with a solitary suspended, rounded seed ; the embryo having a superior 

 radicle, with large and nearly hemispherical fleshy cotyledons. 



