BLAKE—NEW GENUS HEMIBACCHARIS. 545 
tish, alveolate; pistillate heads heterogamous, the outer flowers (9 to 120) 
pistillate, fertile, their corollas with filiform tube, subtruncate or with very 
short, erect, often bidentate limb, much surpassed by the style, or in one species 
distinctly ligulate and exceeding the style, the central 1 to 15 flowers herma- 
phrodite but sterile, with regular tubular 5-toothed corolla and usually 2- 
branched style; staminate heads 8 to 70-flowered, with regular tubular 5- 
toothed corollas, in one species with 5 to 12 outer tubular-filiform pistillate 
flowers; stamens subentire or minutely sagittate at base, with rather long 
elliptic terminal appendages; style branches in the hermaphrodite flowers 
oblong to lanceolate, acute to acuminate, hispidulous, or the style rarely 
undivided, in the pistillate flowers linear, glabrous; fertile achenes compressed, 
rarely trigonous, 2 (rarely 3)-nerved, hispidulous; pistillate pappus setose, 
1-seriate, the bristles capillary; staminate pappus with the bristles often 
dilated at apex. 
Species 15, ranging from Chihuahua to Costa Rica. Type species, Hemibuc- 
charis hieracioides Blake (Baccharis hieractifolia Hemsl.). 
KEY TO SPECIES. 
Lamina of the pistillate corollas wanting or less than 1 mm. long and erect. 
‘Leaves (at least the middle and upper) narrowed to an amplexicaul base. 
Stem densely pubescent with spreading gland-tipped hairs. 
Leaf blades lanceolate to elliptic or elliptic-lanceolate, gradually nar- 
rowed to base__-____--_-_--- eee 1. H. glandulosa. 
Leaf blades oval, rather abruptly contracted into a petioliform base. 
2. H. oaxacana. 
Stem pubescent with eglandular hairs. Leaves broadly ovate. 
3. H. pringlei. 
Leaves petiolate, not amplexicaul. 
Heads larger, the pistillate 7 to 10 mm. high, the staminate 6 to 11 mm. 
high. 
Stem densely pubescent with spreading gland-tipped hairs, 
4. H. hieracioides. 
Stem sparsely hispidulous with incurved eglandular hairs. 
5. H. simplex. 
Heads smaller, 2 to 6 mm. high. 
Plants scandent or subscandent, frutescent; branches usually conspicu- 
ously zigzag; heads in usually small, rounded, cymose panicles ter- 
minating the branches and the numerous wide-spreading branchlets. 
Leaves firmly papery or pergamentaceous, essentially glabrous except 
on the veins, the veinlets prominulous-reticulate on both sides. 
6. H. salmeoides. 
Leaves membranaceous or papery, usually pubescent on the surface 
beneath as well as on the veins, searcely or not prominulous- 
reticulate. 
Heads tiny, 2 to 3.5 mm. high; leaves chiefly ovate or elliptic. 
7. H. hirtella. 
Heads larger, 4 to 6 mm, high, 
Leaves chiefly elliptic or lance-elliptic, less than half as wide as 
long; branches densely spreading-pilose with many-celled 
sordid hairs___________-_-___-_- eee eee 8. H. flexilis. 
Leaves chiefly oval or oval-ovate, more than half as wide as long; 
branches sordid-puberulous, glabrescent______ 9. H. torquis. 
