North American species of Lactarius / L. R. Hesler, Alexander H. Smith.

Subgenus Lactifluus

215

or + fusoid, content "vermiformi-granulari." Gill trama lacking sphaerocysts except near pileus trama. Cuticle of pileus consisting of an
epicutis and hypodermium (a basal layer); epicutis a trichoderm of
filaments 4-4.5 p wide, hyaline or in groups grayish buff, walls scarcely
thickened, apex attenuated to rounded; hypodermium irregular, of
filamentose hyphae flexuous, narrow, interwoven and hyaline; clamps
absent.
Habit, habitat, and distribution.-Under Quercus laurifolia and
Q. virginiana and other hardwoods, in hammocks, July-November,
Florida. Type from Matheson Hammock, September 16, 1942 (FH?),
Dade County, Florida, R. Singer 714.
Observations.-The + date-brown to olive-brown colors and large
spores distinguish this species from L. hygrophoroides, to which it is
closely related. Singer (1948) states that the type is deposited at the
Farlow Herbarium. However, it was not found there nor at the University of Florida at Gainesville. We were able to study a collection
marked "co-type" which is at the Farlow, and was collected November
4, 1942, in Dade County, Florida. Unfortunately, this basidiocarp was
immature when collected. We found very few spores, and no pleurocystidia other than filamentous pseudocystidia. The spores of this
collection were smaller (9-11.5 X 7.5-8.5 ti) than as described by
Singer. Our description is of necessity based entirely on Singer's 1948
account and the specimen mentioned.
55. Lactarius similis sp. nov.
Pileus 4-8 cm latus, "light vinaceous-cinnamon," postea saepe
colorem "light buff" monstrans, subtomentosus demum pruinosus.
Latex albus, constans, lamellas colore subviridi tingens, gustus mitis.
Lamellae pallido-flavae. Stipes albus. Sporae 7-9(10) X 5.5-7(7.5),.
Specimen typicum in Herbarium University of Tennessee conservatum;
legit prope Ramsey Springs, Mississippi, 19 Jun 1959, Thiers 6554
(TENN 35399).
Pileus 4-8 cm broad, convex, depressed, azonate, dry, subtomentose to pruinose, "light vinaceous-cinnamon," often fading to "light
buff" (pale yellow) or "warm buff." Latex white, unchanging, staining
lamellae greenish; taste mild.
Lamellae adnate-subdecurrent, pale yellow, staining greenish,
close or nearly subdistant, narrow.
Stipe 2-3 cm long, 10-14 mm thick, white, subtomentose or
pruinose, solid.
Spores 7-9(10) X 5.5-7(7.5),u, ellipsoid, slightly inequilateral in
profile; prominences about 0.1 u or less high (estimated), with lines