liferae are known to occur in the state, according to the 
taxonomic concepts of Mathias and Constance (1944- 
45). Since more than one-third of these taxa belong to 
the difficult genus Mryngium, this total is susceptible to 
change. 
In his field studies’ of the ethnobotany of the Tara- 
humara centered in the Sierra Madre of southwestern 
Chihuahua, the junior author has given particular atten- 
tion to Umbelliferae. As a result, he obtained material 
of no fewer than twenty taxa (including cytological ma- 
terial of many of them). Four of the collections repre- 
sent apparently undescribed species. The purpose of this 
paper is to put them adequately on record. 
Donnellsmithia silvicola Constance & Bye sp. nov. 
Plantae perennes caulescentes humiles condensatae ; 
caules simplices vel pauciramosae sparsim foliati 8-25 
em. alti e radice palari tumida omnino glabrae; folia 
basalia deltoideo-orbiculata 1-8 cm. longa, 1.5-5 cm. 
lata, trifoliata, foliolis 8 ovalibus orbiculatisve, obtusis 
lobatis vel pinnatifidis diametro 1-2 cm.: petioli 1-8 
cm. longi anguste scarioso-vaginantes; folia caulina ea 
basalia simulantia sed sursum reducta vaginis parum dila- 
tatis: pedunculi usque ad 2 em. longi pauci alternati 
graciles umbellis plerumque lateralibus sessilibus sub- 
sessilibusve; involucrum nullum:; involucellum nullum; 
radii 2—5 filiformes patenti-adscendentes 6-25 mm. longi: 
pedicelli fertiles 0-2, 3-4 mm. longi; flores flavo-virentes ; 
stylopodium depressum, stylis brevissimis ; carpophorum 
usque ad basim bipartitum; fructus immaturus ovoideo- 
orbicularis 1.5 mm. longus, 2 mm. latus ad apicem ver- 
* Financial support between 1971 and 1974 was generously extended 
by the Botanical Museum and the Department of Biology, Harvard 
University, the National Geographic Society and the National Science 
Foundation Grant GB-35047 for Improvement of Doctoral Disserta- 
tion Research. 
[ 226 | 
