5. R. arvensis, Aust. Thallus much divided, 3--9" broad, papillose-reticulate, dull green both sides, becoming fuscous above, the flat margins at length purple; divisions sulcate, dichotomous, the linear-elliptic or subspatulate lobes acutish and obsoletely emarginate; cilia whitish, very short and inconspicuous or nearly wanting; capsules aggregated toward the apex; spores 71--84 broad, dark fuscous, reticulate, with pellucid margin.--Var. HiRTA, Aust., decidedly ciliate and with spine-like hairs scattered over the upper surface; divisions broader, more obtuse; spores nearly black, larger (84--101 ) and smoother.--Cultivated fields and (the var.) rocky places, Closter, N. J.

(_Austin_).

6. R. Lescuriana, Aust. Stellately or subcruciately divided, the obcordate or cuneate-linear divisions 2--6" long, punctate-reticulate, subglaucous or ashy-green both sides or becoming purple beneath, the slightly concave lobes emarginate, closely ciliate with short obtuse spine-like white hairs; capsules scattered, chiefly near the base of the divisions; spores 71--83 broad, dark brown, reticulate, not margined.--Cultivated fields and rocky grounds, N. J. to Ill., and southward.

-- 2. SPONGDES. _Thallus with large air-cavities usually opening by pits through the upper surface, and with slight depressions over the capsules which are prominent beneath; spores 41--51 broad, obtusely angular or globose; terrestrial._

7. R. crystallina, L. Orbicular, 6--9" broad, the obcordate or cuneate divisions bifid or 2-lobed, flat above and the surface much broken up into pits, the margins subcrenate; capsules scattered; spores issuing through the upper surface.--On mud flats, Ill. (_Hall_), west and southward. (Eu.)

8. R. lutescens, Schwein. Orbicular, 1--1' in diameter, light green; divisions 6--8, linear, 2--3 times forked, narrowly channelled, obcordate and thickened at the apex, with delicate whitish obliquely ovate appressed scales, rootlets wanting beneath above the middle; fruiting plant unknown.--Dried up pools and ditches, Canada to Mo., and southward. An a.n.a.logous form has been developed by Lindberg from R.

natans.

9. R. tenuis, Aust. Thallus thin, olive or yellowish-green, shining, the 2--4 divisions roundish-obovate, 2--4" long, flat, with sinuate margins, green beneath with a slender costa and few rootlets; capsule very delicate, closely adherent to the substance of the thallus, minutely apiculate; spores round or short-oval, conspicuously depressed at one end when dry.--Wet ground in open woods, Closter and Lawrence, N. J. (_Austin_), and Mo. (_Hall_).

-- 3. RICCIeLLA. _Thallus linear, dichotomous, floating or rarely terrestrial; capsule protuberant from the lower surface._

10. R. fluitans, L. Thallus often in extended patches, thin, green, radiately expanding, the often imbricate divisions --1" wide, parallel-nerved, flat, without rootlets, cavernous only toward the slightly dilated very obtuse or subtruncate apex; capsules present only in some terrestrial forms, very prominent below, rupturing beneath the apex.--Very variable. The most notable form is var. SULLIVaNTI, Aust., with divisions about " wide, channelled, cavernous throughout, the margins crisped-crenulate, and rootlets numerous on the costa tumid with abundant capsules, which are tipped with a long funnel-mouthed point; spores obscurely angled, reticulate and margined. (R. Sullivanti, _Aust._)--In ponds or ditches or growing in wet places upon the ground; the variety often in cultivated fields. (Eu.)

-- 4. RICCIOCaRPUS. _Thallus obcordate, floating or rarely terrestrial; capsules not protruding, at length exposed by a cleft in the central groove._

11. R. natans, L. (Pl. 22.) Divisions obcordate or cuneate, broadly emarginate, 3--6" long, purplish, very narrowly channelled, with numerous uniform air-cavities beneath the epidermis, rooting toward the base and at length with dark purple scales beneath the apex; capsules in 1 or 2 rows beneath the groove; spores black, angular, strongly papillose.--Canada to the Gulf. (Eu.)

2. SPHaeROCaRPUS, Micheli. (Pl. 22.)

Thallus lobed, without costa or epidermis. Involucres sessile, obconic or pyriform, perforated at the apex, continuous with the thallus at base. Calyptra closely investing the single globose indehiscent capsule, crowned with a deciduous point. Spores globose, muriculate, remaining united in a coccus. Antheridia borne in follicular bodies on the surface of a separate thallus.--An anomalous genus, perhaps more closely related to the Jungermanniaceae. (Name from sfa????, _a sphere_, and ?a?p??, _fruit_.)

1. S. terrestris, Smith. Thallus...o...b..cular, 3--6" broad, covered by the cl.u.s.tered inflated involucres, which are nearly 1" long, 3--4 times the length of the capsule; coccus 102--127 wide, indistinctly lobed. (S.

Michelii, _Bellardi_.)--In cultivated fields, mostly southern. (Eu.)

ADDITIONS AND CORRECTIONS.

Page 59.--ARGEMONE MEXICANA. Collected at Merodosia, Ill., with white flowers, by _A. B. Seymour_.

Page 75.--Insert after Cleome integrifolia--

C. SPINSA, L. Viscid-p.u.b.escent, 3--4 high; a pair of short stipular spines under the petiole of each leaf; leaflets 5--7, oblong-lanceolate; flowers large, rose-purple to white; stamens 2--3' long; stipe of the linear pod about 2' long. (C. pungens, _Willd._)--An escape from cultivation, near Mt. Carmel, Ill. (_Schneck_), and in waste grounds southward; also on ballast. (Int. from Trop. Amer.)

Page 86.--Arenaria Grnlandica. Found on Mt. Desert Island, Maine (_Rand_).

Page 87.--Stellaria borealis. In the mountains of northern N. J.

S. humifusa. This species has also been found on Cranberry Island, near Mt. Desert, Maine, by _J. H. Redfield_.

Page 91.--Under Talinum teretifolium add the character--style equalling the stamens.--Insert

2. T. calycnum, Engelm. Leaves somewhat broader; flowers and capsules larger; stamens 30 or more; style twice longer than the stamens, declined.--Central Kan. to W. Tex.

Under Claytonia insert--

3. C. Chamissnis, Esch. Weak, proc.u.mbent or ascending, rooting below and perennial by lateral and terminal filiform runners; leaves several pairs, oblong-spatulate, 1--2' long; inflorescence racemosely 1--9-flowered; petals pale rose-color; capsule small, 1--3-seeded.--In a cold ravine, Winona Co., Minn.; in the mountains from Colorado north and westward.

Page 211.--Hydrocotyle Americana. Add--propagating by filiform tuberiferous stolons.

Page 230.--Insert after the genus Dipsacus--

2. SCABIOSA, Tourn. SCABIOUS.

Characters of Dipsacus, but the green leaves of the involucre and involucels not rigid nor spinescent. (Name from _scabies_, the itch, from its use as a remedy.)

S. AUSTRaLIS, Wulf. Perennial, spa.r.s.ely branched, nearly glabrous, 1--3 high; leaves narrowly lanceolate to linear, the lower oblanceolate, slightly toothed or entire; heads short-oblong; calyx obtusely short-lobed; corolla pale blue.--Central N. Y. and Penn.; rare.

(Adv. from Eu.)

Page 395.--After OROBANCHE MINOR insert--

O. RAMSA, L. Often branched, 6' high or less, of a pale straw-color; flowers 3-bracteate, the lateral bracts small; calyx 4-toothed, split at the back; corolla pale blue, 6--8" long.--On the roots of hemp and tobacco; Ky. (Int. from Eu.)

Page 421.--After LAMIUM PURPUREUM insert--

L. INTERMeDIUM, Fries. Resembling L. purpureum, but the calyx-teeth longer than the tube, the rather narrower corolla without a hairy ring within near the base, and the nutlet longer (3 times as long as broad).--Cultivated fields near Hingham, Ma.s.s. (_C. J. Sprague_). (Adv.

from Eu.)

Page 427.--Insert in the generic key--

5. Cladothrix. Flowers perfect, minute, axillary. Densely white-tomentose.

Page 430.--Insert after the genus Frlichia--

5. CLADoTHRIX, Nutt.

Flowers perfect, 3-bracted. Sepals 5, erect, rigid-scarious, somewhat pilose. Stamens 5, the filaments united at base; anthers large, 1-celled. Stigma large, capitate, 2-lobed. Utricle globose, indehiscent.--Densely stellate-tomentose low herbs or woody at base, with opposite petiolate leaves and very small flowers solitary or few in the axils. (Name from ???d??, _a branch_, and ????, _hair_, for the branching tomentum.)

1. C. lanuginsa, Nutt. Prostrate or ascending, much branched; leaves round-obovate to rhomboidal, 3--10" long.--Central Kan. (_Meehan_) and southwestward.

Page 435.--Salsola Kali. This species has been found in Emmet Co., Iowa (_Cratty_), at Yankton, Dak. (_Bruhin_), and in river-bottoms in N. W.

Neb. and central Dak.

Page 437.--After Eriogonum annuum insert--

2. E. Alleni, Watson. Perennial, white-tomentose throughout, the tall scape-like stem repeatedly dichotomous above; radical leaves lanceolate, long-petiolate, the upper in whorls of 4 or 5, ovate to oblong-ovate, very shortly petiolate, much reduced above; involucres mostly sessile; flowers glabrous, yellow, the segments elliptical.--Near White Sulphur Springs, W. Va. (_T. F. Allen_).

Page 445.--Asarum Canadense. In this species there are rudimentary subulate petals, alternate with the calyx-lobes.

Page 463.--Celtis Mississippiensis. Common in low river-bottoms of W.

Mo. (_F. Bush_); described as having a very smooth trunk, like a sycamore, and soft yellowish brittle wood, not coa.r.s.e-grained as in C.