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The floral anatomy of fourteen genera and twenty-one species of the Solanaceae was examined. The arrangement of the genera is according to Wettstein in Engler and Prantl's Die Naturlichen Pflanzenfamilien. In the order of their complexity, these genera include Nicandra, Lycium, Atropa, Hyoscyamus, Physalis, Capsicum, Solanum, Lycopersicon, Datura, Nicotiana, Petunia, Nierembergia, Salpiglossis, and Schizanthus. The following evolutionary tendencies were noted: actinomorphy to zygomorphy; reduction of fertile stamens from five to two; and reduction in the number of adaxial bundles from two per carpel to one for two carpels. Despite these variations, the floral anatomy follows the same basic plan in all the species studied. The siphonostele generally becomes continuous after the divergences to each of the first three floral sets, and the carpellary bundles are formed from the remaining vascular tissue. Because the adaxial bundles are amphicribral and accompanied by gaps in the vascular cylinder, they are fo...

Oviposition and feeding of the tobacco hornworm arc almost entirely restricted to plants of the family Solinaceae. Oviposition appears to be initiated by olfactory stimuli widely distributed in this plant family, and consequently it, is largely suppressed in the absence of host plants or after excision of the antennae. Both in the field and laboratory, the moths preferred tomato foliage over other solanaceous plants for oviposition. Larval feeding appears to be governed by gustatory stimuli common to plants of this family. On certain ones, such as Nicandra and Petunia , feeding and growth are limited by the presence of repellents or toxins. Some limited feeding occurred on certain nonsolanaceous plants after various periods of starvation.

\TICANDRA PHYSALOIDES is the solitary species of its genus or J V even tribe. Like some of its nearest relatives in Nicotiana it is a native of Peru and Chile. Like them, too, it has become nearly cosmopolitan in cultivation in the last 200 years. It is widely naturalized in the tropics. It was introduced into gardens in this country in 1759 and is still a favourite botanic garden plant. In cultivation and as an escape four completely interfertile 'varieties', or rather variants, can be recognized and we are indebted for them to the following sources: (i) typica, corresponding to the figure in Curtis's 'Botanical Magazine' (No. 2458): from the Botanic Gardens of Kew (4 plants) and of Montreal (30 plants); and collected for us by Dr. S. C. Harland near Lima (6 plants). (ii) violacea, having stronger pigmentation of stem, petiole, calyx, leafhairs, and seeds than typica but intergrading polygenically with it; erroneously described by Lemoine (1906) as a distinct species: from Kew Gardens (10 plants). (iii) immaculata, lacking the corolla spot and the leaf-haii» and cotyledon pigmentation; a recessive single-gene variant, heterozygotes selfed having given us 307 normal to 100 spotless (cf. Dahlgren, 1924): collected in Malabar and from Kew Gardens (22 plants), (iv) alba, with white instead of blue flowers probably also a recessive singlegene variant: from Cambridge Botanic Gardens (6 plants). The first three variants were also found as escapes from earlier cultivation at Merton.

The known withanolide nicandrenone (1) is primarily responsible for the IN VITRO cytotoxicity of extracts prepared from NICANDRA PHYSALODES (Solanaceae).

Summary. Infection of numerous species of Solanaceae by Synchylrium endobioticum has been obtained using Glynne's “green wart” method. Plants grown in contaminated soil did not show infection. The following new hosts are recorded: Solanum dulcamara var. villosissimum, Nicandra physalodes, Solanum dulcamara alba, Solanum nodiflorum and Solanum villosum. In certain hosts the fungus may occur in the tissues with little or no external sign of its presence. I am indebted to Dr W. B. Brierley for helpful criticism and suggestions received during the course of this work; and to the Director, Research and Experimental Station, Cheshunt, Herts, The Director. Royal Botanic Gardens, Kew, Surrey, The Regius Keeper, Royai Botanic Gardens, Edinburgh, and Martin H. Sutton, Esq., Erlegh Park, Whiteknights, Reading, for seed and tubers used in the experiments.

Taxonomic relationships in the Solanaceae have been discussed based on chromosomal criteria of 45 species; including three new records; belonging to 15 genera representing eight of the 14 currently recognized tribes; and their phylogeny based on variation in chromosome number is proposed. In contrast to the traditional subfamilial delimitation of the family (Murray 1945, D'Arcy 1979, 1991, Armstrong 1986) cytological data indicate that subfamily Cestroideae is less evolved than subfamily Solanoideae. These data further support the isolation of Cestrum in a separate tribe. The isolation of tribe Salpiglossideae in a separate family as proposed by Hutchinson (1973) and the delimitation of both Datura and Hyoscayamus as two separate tribes as done by D'Arcy (1991) is strongly supported by cytological data. In agreement with both Wettstein (1895) and D'Arcy (1991) the delimitation of Nicandra in a separate tribe is further recommended. However, the separation of Atropa and Lycium from the tribe solaneae are not likely to be justified based on cytological ground.

In the list of chromosome counts for the genus Crocus (Brighton, C. A., Mathew, B. F. & Marchant, C. J. in Kew Bull. 28(3): 451-464 (1973)) counts of 2n = 28 and 2n = 30 were reported for two collections of Crocus medius from Monte Alto and the Ligurian Alps in Italy. A more detailed study of the karyotypes has shown that B-chromosomes occur in this species and that one pair of chromosomes has very distinct secondary constrictions giving the impression of two separate chromosomes lying close together when in fact there is only one. The correct numbers for the plants examined are 2n = 24 + 2B and 2n = 24 + 5B respectively. Both karyotypes are illustrated in Figure IA & B and consist of three pairs of median chromosomes, one pair of chromosomes with two secondary constrictions, one pair of sub-median chromosomes and seven pairs with subterminal constrictions. From 2-5 B-chromosomes were also present in the two collections examined. Pair IV of both karyotypes has three distinct constrictions (arrowed). It is uncertain which of these is the centromere, but meiotic studies might give some indication. Chromosomes of this kind are very unusual. If one supposes the centromere to be the central constriction, then there is a possibility that these could be iso-chromosomes similar to those found in Nicandra by Darlington & JanakiAmmal in Ann. Bot. II, 9(35): 267-28 (1945). Here again, meiosis would need to be observed in detail to see whether these chromosomes pair normally, or whether each chromosome consists of identical arms which are capable of pairing together.

On the Atherton Tableland, Queensland, apple of Peru (Nicandra physalodes) is a problem weed in maize. The competitive effects of N, physalodes, the effectiveness of various control measures and the residual life of atrazine (2-chloro-6-ethylamino-4-isopropylamino-I ,3,5-triazine) were investigated in three experiments each repeated over two seasons. In 1973 (a late season) populations of N. physalodes as low as 4.7 m-2 reduced yields by about 35 per cent and would have caused harvester impedance in a commercial situation. In 1973-74 (an early season) N. physalodes had less effect on yield but would still have impeded harvesting. In 1973 atrazine used pre-emergence at 2.24 kg a.i. ha-1 was sufficient for satisfactory weed control. During 1973-74 when weed growth was prolonged after crop ripening by wet weather a split application of atrazine applied at 1 .12 kg a.i, ha-1 pre-emergence followed six weeks later by a further 1.12 kg a.i. ha-1 was better in controlling weeds at harvest than the single pre-emergence application. Under the conditions of these experiments atrazine used at the above rates did not cause damage to oats planted immediately after the maize harvest.

THE wildfire disease of tobacco, caused by Bacterium tabacum, was first described in the United States in 1916; since then it has been reported from many parts of the world and has been the subject of extensive and detailed scientific investigations in many countries. The host range of the organism is a point of considerable importance and it has been found that many species of plants can be artificially infected with B. tabacum, with the production of definite pathological leaf symptoms. Yet, so far as I am aware, there are only three records (cowpea1, tomato2, and cucumber3) of the natural infection of plants other than tobacco. It is therefore of interest that I have found Nicandra physaloides, Gaertn. to be abundantly infected with wildfire in tobacco fields at Balfour in the East Cape Province, South Africa. This annual solanaceous weed is not indigenous but is widespread throughout arable lands. The infection was first observed in the late summer of 1932 among plants growing between the tobacco rows in a damp corner of the field; the following season, wildfire was very prevalent in tobacco and practically all the Nicandra plants throughout the same field showed wildfire spotting.